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Kruijt N, van den Bersselaar LR, Hopman MTE, Snoeck MMJ, van Rijswick M, Wiggers TGH, Jungbluth H, Bongers CCWG, Voermans NC. Exertional Heat Stroke and Rhabdomyolysis: A Medical Record Review and Patient Perspective on Management and Long-Term Symptoms. SPORTS MEDICINE - OPEN 2023; 9:33. [PMID: 37204519 DOI: 10.1186/s40798-023-00570-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 04/19/2023] [Indexed: 05/20/2023]
Abstract
INTRODUCTION Exertional heat stroke (EHS) is a medical emergency, occurring when the body generates more heat than it can dissipate, and frequently associated with exertional rhabdomyolysis (ERM). In the present study we aimed to (I) identify clinical features and risk factors, (II) describe current prehospital management, (III) investigate long-term outcomes including the impact on mental health, and review the guidance received during restarting activities. We hope that our approach will improve individual and organizational heat illness preparedness, and improve follow-up care. METHODS We performed a prospective online survey and retrospective medical record review among athletes and military personnel with an episode of EHS/ERM in the Netherlands between 2010 and 2020. We evaluated prehospital management, risk factors, clinical features and long-term outcomes at 6 and 12 months after the event, including mental health symptoms. Furthermore, we investigated what guidance participants received during follow-up, and assessed the patients' perspective on these outcomes. RESULTS Sixty participants were included, 42 male (70%) and 18 female (30%), of which 47 presented with EHS (78%) and 13 with ERM (22%). Prehospital management was inconsistent and in the majority of participants not conducted according to available guidelines. Self-reported risk factors included not feeling well-acclimatized to environmental heat (55%) and peer pressure (28%). Self-reported long-term symptoms included muscle symptoms at rest (26%) or during exercise (28%), and neurological sequelae (11%). Validated questionnaires (CIS, HADS and SF-36) were indicative of severe fatigue (30%) or mood/anxiety disorders (11%). Moreover, 90% expressed a lack of follow-up care and that a more frequent and intensive follow-up would have been beneficial for their recovery process. CONCLUSION Our findings indicate major inconsistencies in the management of patients with EHS/ERM, emphasizing the compelling need for implementing standardized protocols. Based on the results of long-term outcome measures, we recommend to counsel and evaluate every patient not only immediately after the event, but also in the long-term.
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Affiliation(s)
- Nick Kruijt
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10 (Route 652), 6525 GA, Nijmegen, The Netherlands.
- Department of Primary and Community Care, Radboudumc, Nijmegen, The Netherlands.
| | - L R van den Bersselaar
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10 (Route 652), 6525 GA, Nijmegen, The Netherlands
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - M T E Hopman
- Department of Physiology, Radboudumc, Nijmegen, The Netherlands
| | - M M J Snoeck
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - M van Rijswick
- Department of Exercise Medicine and Exercise Physiology, Royal Dutch Army, Utrecht, The Netherlands
| | - T G H Wiggers
- Department of Sports Medicine, Anna Hospital, Geldrop, The Netherlands
| | - H Jungbluth
- Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, UK
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - C C W G Bongers
- Department of Physiology, Radboudumc, Nijmegen, The Netherlands
| | - N C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10 (Route 652), 6525 GA, Nijmegen, The Netherlands
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Kane DA, Foo ACY, Noftall EB, Brebner K, Marangoni DG. Lactate shuttling as an allostatic means of thermoregulation in the brain. Front Neurosci 2023; 17:1144639. [PMID: 37250407 PMCID: PMC10217782 DOI: 10.3389/fnins.2023.1144639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 04/18/2023] [Indexed: 05/31/2023] Open
Abstract
Lactate, the redox-balanced end product of glycolysis, travels within and between cells to fulfill an array of physiologic functions. While evidence for the centrality of this lactate shuttling in mammalian metabolism continues to mount, its application to physical bioenergetics remains underexplored. Lactate represents a metabolic "cul-de-sac," as it can only re-enter metabolism by first being converted back to pyruvate by lactate dehydrogenase (LDH). Given the differential distribution of lactate producing/consuming tissues during metabolic stresses (e.g., exercise), we hypothesize that lactate shuttling vis-à-vis the exchange of extracellular lactate between tissues serves a thermoregulatory function, i.e., an allostatic strategy to mitigate the consequences of elevated metabolic heat. To explore this idea, the rates of heat and respiratory oxygen consumption in saponin-permeabilized rat cortical brain samples fed lactate or pyruvate were measured. Heat and respiratory oxygen consumption rates, and calorespirometric ratios were lower during lactate vs. pyruvate-linked respiration. These results support the hypothesis of allostatic thermoregulation in the brain with lactate.
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Affiliation(s)
- Daniel A. Kane
- Department of Human Kinetics, St. Francis Xavier University, Antigonish, NS, Canada
| | - Alexander C. Y. Foo
- Department of Chemistry, St. Francis Xavier University, Antigonish, NS, Canada
| | - Erin B. Noftall
- Department of Human Kinetics, St. Francis Xavier University, Antigonish, NS, Canada
| | - Karen Brebner
- Department of Psychology, St. Francis Xavier University, Antigonish, NS, Canada
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Yezli S, Khan AH, Yassin YM, Khan AA, Alotaibi BM, Bouchama A. Human tolerance to extreme heat: evidence from a desert climate population. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2023:10.1038/s41370-023-00549-7. [PMID: 37138035 DOI: 10.1038/s41370-023-00549-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 04/12/2023] [Accepted: 04/17/2023] [Indexed: 05/05/2023]
Abstract
BACKGROUND Ambient temperatures exceeding 40 °C are projected to become common in many temperate climatic zones due to global warming. Therefore, understanding the health effects of continuous exposure to high ambient temperatures on populations living in hot climatic regions can help identify the limits of human tolerance. OBJECTIVE We studied the relationship between ambient temperature and non-accidental mortality in the hot desert city of Mecca, Saudi Arabia, between 2006 and 2015. METHODS We used a distributed lag nonlinear model to estimate the mortality-temperature association over 25 days of lag. We determined the minimum mortality temperature (MMT) and the deaths that are attributable to heat and cold. RESULTS We analyzed 37,178 non-accidental deaths reported in the ten-year study period among Mecca residents. The median average daily temperature was 32 °C (19-42 °C) during the same study period. We observed a U-shaped relationship between daily temperature and mortality with an MMT of 31.8 °C. The total temperature-attributable mortality of Mecca residents was 6.9% (-3.2; 14.8) without reaching statistical significance. However, extreme heat, higher than 38 °C, was significantly associated with increased risk of mortality. The lag structure effect of the temperature showed an immediate impact, followed by a decline in mortality over many days of heat. No effect of cold on mortality was observed. IMPACT STATEMENT High ambient temperatures are projected to become future norms in temperate climates. Studying populations familiar with desert climates for generations with access to air-conditioning would inform on the mitigation measures to protect other populations from heat and on the limits of human tolerance to extreme temperatures. We studied the relationship between ambient temperature and all-cause mortality in the hot desert city of Mecca. We found that Mecca population is adapted to high temperatures, although there was a limit to tolerance to extreme heat. This implies that mitigation measures should be directed to accelerate individual adaptation to heat and societal reorganization.
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Affiliation(s)
- Saber Yezli
- Biostatistics, Epidemiology and Scientific Computing Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
- Global Centre for Mass Gathering Medicine, Ministry of Health, Riyadh, 12341, Saudi Arabia.
- Experimental Medicine Department, King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences 11481, Riyadh, Saudi Arabia.
| | - Altaf H Khan
- Department of Biostatistics and Bioinformatics, King Abdullah International Center for Medical Research / King Saud bin Abdulaziz University for Health Sciences 11481, Riyadh, Saudi Arabia
| | - Yara M Yassin
- Global Centre for Mass Gathering Medicine, Ministry of Health, Riyadh, 12341, Saudi Arabia
| | - Anas A Khan
- Global Centre for Mass Gathering Medicine, Ministry of Health, Riyadh, 12341, Saudi Arabia
- Department of Emergency Medicine, College of Medicine, King Saud University, Riyadh, 12372, Saudi Arabia
| | - Badriah M Alotaibi
- Global Centre for Mass Gathering Medicine, Ministry of Health, Riyadh, 12341, Saudi Arabia
| | - Abderrezak Bouchama
- Experimental Medicine Department, King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences 11481, Riyadh, Saudi Arabia.
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Martínez-Noguera FJ, Cabizosu A, Marín-Pagán C, Alcaraz PE. Body surface profile in ambient and hot temperatures during a rectangular test in race walker champions of the World Cup in Oman 2022. J Therm Biol 2023; 114:103548. [PMID: 37344022 DOI: 10.1016/j.jtherbio.2023.103548] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 06/23/2023]
Abstract
There is current interest in infrared thermography as a method to assess changes in body surface temperature to determine thermoregulatory mechanisms, especially in endurance sports. The aim of this study was to evaluate the effect of two environmental temperatures (17 and 28°C) on body surface temperature in different anterior and posterior aspects of the body during a rectangular test in international walkers of the Spanish National Team. Three international walkers performed a rectangular test, where body temperature was measured at rest, and after the 5th, 10th and 15th run using an infrared thermographic camera in room temperatures at 17 and 28°C. In addition, oxygen consumption was measured simultaneously. ANOVA detected a group × time interaction in the chest and abdomen (right and left), left back and right calf (p = < 0.05), with a trend in the right hamstring (p = 0.053) when comparing 17°C and 28°C. ANOVA detected no significant group × time interaction (p = 0.853) but there was a significant group effect (p = 0.022). The eleven degrees increase in ambient temperature (17 to 28°C) produces changes in almost all anatomical zones, but not homogeneously in international walkers during a rectangular test. This indicates that metabolic and blood flow changes are different depending on the anatomical zone measured.
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Affiliation(s)
- Francisco Javier Martínez-Noguera
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos, N° 135 UCAM, 30107, Murcia, Spain.
| | - Alessio Cabizosu
- THERMHESC Group, Ribera Hospital de Molina San Antonio Catholic University of Murcia (UCAM), Spain.
| | - Cristian Marín-Pagán
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos, N° 135 UCAM, 30107, Murcia, Spain.
| | - Pedro E Alcaraz
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos, N° 135 UCAM, 30107, Murcia, Spain.
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Rivera-Brown AM, Correa JJ, Micheo WF. Return-to-Competition Progression After Exertional Heat Stroke in an Adolescent Runner: A Case Report. J Athl Train 2023; 58:349-354. [PMID: 35622950 PMCID: PMC11215635 DOI: 10.4085/1062-6050-0583.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A 14-year-old runner indigenous to the tropics collapsed during his first 10-km race in a hot and humid climate. Dizziness, stumbling, and loss of consciousness were symptoms of exertional heat stroke. Two days postcollapse, blood tests revealed elevated hepatic transaminases consistent with hepatic injury. We discuss the return-to-competition progression, which included a gradual increase in exercise duration, initially in a cool and then in a tropical climate, and 2 field-based (wet-bulb globe temperature > 29.0°C) running evaluations that simulated the environmental conditions and training intensity the athlete would encounter in his sport. The thermoregulatory results guided the training progression, his tolerance to running in the heat improved, blood values normalized, and he was cleared to compete in a tropical climate. This exploration case report presents a novel field-based protocol that replicates the physiological demands of training in the tropics to evaluate thermoregulatory responses during exercise-heat stress in young runners after exertional heat stroke to facilitate a safe return to competition.
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Affiliation(s)
- Anita M. Rivera-Brown
- Department of Physical Medicine, Rehabilitation and Sports Medicine, Center for Sports Health and Exercise Sciences, San Juan
- Department of Physiology, University of Puerto Rico, School of Medicine, San Juan
| | - José J. Correa
- Department of Physical Medicine, Rehabilitation and Sports Medicine, Center for Sports Health and Exercise Sciences, San Juan
| | - William F. Micheo
- Department of Physical Medicine, Rehabilitation and Sports Medicine, Center for Sports Health and Exercise Sciences, San Juan
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de Korte JQ, Eijsvogels TMH, Hopman MTE, Bongers CCWG. Thermoregulatory, Cardiovascular and Perceptual Responses of Spectators of a Simulated Football Match in Hot and Humid Environmental Conditions. Sports (Basel) 2023; 11:78. [PMID: 37104152 PMCID: PMC10140829 DOI: 10.3390/sports11040078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/17/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
Major sporting events are often scheduled in thermally challenging environments. The heat stress may impact athletes but also spectators. We examined the thermal, cardiovascular, and perceptual responses of spectators watching a football match in a simulated hot and humid environment. A total of 48 participants (43 ± 9 years; n = 27 participants <50 years and n = 21 participants ≥50 years, n = 21) watched a 90 min football match in addition to a 15 min baseline and 15 min halftime break, seated in an environmental chamber (Tair = 31.9 ± 0.4 °C; RH = 76 ± 4%). Gastrointestinal temperature (Tgi), skin temperature (Tskin), and heart rate (HR) were measured continuously throughout the match. Mean arterial pressure (MAP) and perceptual parameters (i.e., thermal sensation and thermal comfort) were scored every 15 min. Tri (37.3 ± 0.4 °C to 37.4 ± 0.3 °C, p = 0.11), HR (76 ± 15 bpm to 77 ± 14 bpm, p = 0.96) and MAP (97 ± 10 mm Hg to 97 ± 10 mm Hg, p = 0.67) did not change throughout the match. In contrast, an increase in Tskin (32.9 ± 0.8 °C to 35.4 ± 0.3 °C, p < 0.001) was found. Further, 81% of participants reported thermal discomfort and 87% a (slightly) warm thermal sensation at the end of the match. Moreover, the thermal or cardiovascular responses were not affected by age (all p-values > 0.05). Heat stress induced by watching a football match in simulated hot and humid conditions does not result in substantial thermal or cardiovascular strain, whereas a significant perceptual strain was observed.
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Affiliation(s)
- Johannus Q. de Korte
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Thijs M. H. Eijsvogels
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Maria T. E. Hopman
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
| | - Coen C. W. G. Bongers
- Department of Medical Biosciences, Radboud University Medical Center, 6500VC Nijmegen, The Netherlands
- School of Sport and Exercise, Health Promotion & Performance, HAN University of Applied Sciences, 6525AJ Nijmegen, The Netherlands
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Short-term heat acclimation protocols for an aging population: Systematic review. PLoS One 2023; 18:e0282038. [PMID: 36862716 PMCID: PMC9980817 DOI: 10.1371/journal.pone.0282038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/06/2023] [Indexed: 03/03/2023] Open
Abstract
INTRODUCTION Elderly and sedentary individuals are particularly vulnerable to heat related illness. Short-term heat acclimation (STHA) can decrease both the physical and mental stress imposed on individuals performing tasks in the heat. However, the feasibility and efficacy of STHA protocols in an older population remains unclear despite this population being particularly vulnerable to heat illness. The aim of this systematic review was to investigate the feasibility and efficacy of STHA protocols (≤twelve days, ≥four days) undertaken by participants over fifty years of age. METHODS Academic Search Premier, CINAHL Complete, MEDLINE, APA PsycInfo, and SPORTDiscus were searched for peer reviewed articles. The search terms were; (heat* or therm*) N3 (adapt* or acclimati*) AND old* or elder* or senior* or geriatric* or aging or ageing. Only studies using primary empirical data and which included participants ≥50 years of age were eligible. Extracted data includes participant demographics (sample size, gender, age, height, weight, BMI and [Formula: see text]), acclimation protocol details (acclimation activity, frequency, duration and outcome measures taken) and feasibility and efficacy outcomes. RESULTS Twelve eligible studies were included in the systematic review. A total of 179 participants took part in experimentation, 96 of which were over 50 years old. Age ranged from 50 to 76. All twelve of the studies involved exercise on a cycle ergometer. Ten out of twelve protocols used a percentage of [Formula: see text] or [Formula: see text] to determine the target workload, which ranged from 30% to 70%. One study-controlled workload at 6METs and one implemented an incremental cycling protocol until Tre was reached +0.9°C. Ten studies used an environmental chamber. One study compared hot water immersion (HWI) to an environmental chamber while the remaining study used a hot water perfused suit. Eight studies reported a decrease in core temperature following STHA. Five studies demonstrated post-exercise changes in sweat rates and four studies showed decreases in mean skin temperature. The differences reported in physiological markers suggest that STHA is viable in an older population. CONCLUSION There remains limited data on STHA in the elderly. However, the twelve studies examined suggest that STHA is feasible and efficacious in elderly individuals and may provide preventative protection to heat exposures. Current STHA protocols require specialised equipment and do not cater for individuals unable to exercise. Passive HWI may provide a pragmatic and affordable solution, however further information in this area is required.
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Heatherly AJ, Caputo JL, Johnson SL, Fuller DK. Heat Acclimation Knowledge among Recreational Runners. Sports (Basel) 2023; 11:sports11020049. [PMID: 36828334 PMCID: PMC9965591 DOI: 10.3390/sports11020049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/10/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Heat acclimation (HA) is the foremost method of preventing exertional heat illness during exercise in hot and humid environments. However, the prevalence of HA training and its associated knowledge is not currently known in recreational running populations. The purpose of this study was to determine the knowledge of recreational runners toward HA. A survey consisting of 38 questions that required approximately 10-15 min to complete was disseminated to running clubs throughout the Southeastern United States. Questions were designed to collect data on participant demographics, yearly training habits, and HA knowledge. Recreational runners (N = 125) demonstrated a lack of knowledge toward proper HA training and its associated benefits. Participants largely received HA advice from their peers (31.2%) and reported no professional guidance in their training (79.2%). Finally, participants' beliefs toward proper HA training differed among training groups with moderate and high groups perceiving greater frequency, miles/wk, and min/wk as appropriate for HA compared to the low group (p ≤ 0.05). Due to the warmer temperatures and higher relative humidity experienced in the southeastern, southwestern, and mid-Atlantic locations of the United States and throughout certain regions of the European Union, governing bodies in sport and exercise science should develop more educational initiatives to convey the importance and advantages of HA, especially when runners are training for major marathons that are typically held in the late spring and early fall seasons.
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Affiliation(s)
| | - Jennifer L. Caputo
- Department of Health and Human Performance, Middle Tennessee State University, Murfreesboro, TN 37132, USA
| | - Samantha L. Johnson
- Department of Health and Human Performance, Middle Tennessee State University, Murfreesboro, TN 37132, USA
| | - Dana K. Fuller
- Department of Psychology, Middle Tennessee State University, Murfreesboro, TN 37132, USA
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Manning CN, Benjamin CL, Sekiguchi Y, Butler CR, Szymanski MR, Stearns RL, Armstrong LE, Lee EC, Casa DJ. Environmental Stress Symptoms during Heat Acclimatization, Heat Acclimation, and Intermittent Heat Training. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3219. [PMID: 36833912 PMCID: PMC9962616 DOI: 10.3390/ijerph20043219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Athletes training in heat experience physiological and perceptual symptoms that risk their safety and performance without adaptation. PURPOSE We examined the changes in environmental symptoms, assessed with the Environmental Symptoms Questionnaire (ESQ), during heat acclimatization (HAz), heat acclimation (HA), and intermittent heat training (HT). METHODS Twenty-seven participants (mean ± standard deviation [M ± SD], age of 35 ± 12 y, VO2max of 57.7 ± 6.8 mL·kg-1·min-1) completed five trials involving 60 mins of running (60% vVO2max) followed by a 4 km time trial in heat (M ± SD, temperature of 35.5 ± 0.7 °C, humidity of 46.4 ± 1.5%). The trials occurred at baseline, post-HAz, post-HA, at week 4 of HT (post-HT4), and at week 8 of HT (post-HT8). The participants completed HT once/week (HTMIN), completed HT twice/week (HTMAX), or did not complete HT (HTCON). ESQ symptoms, thermal sensation (TS), and heart rate (HR) were measured pre- and post-trial. RESULTS Post-ESQ symptoms improved post-HA (3[0.40, 4.72], p = 0.02) and post-HAz (3[0.35, 5.05], p = 0.03) from baseline. During HT, symptoms improved in the HTMAX group and worsened in the HTMIN and HTCON groups. Symptoms improved in the HTMAX group versus the HTCON group at post-HT8 (4[1.02, 7.23], p = 0.012). Higher TS and HR values were weakly associated with ESQ symptoms during HT (r = 0.20, p = 0.04), only explaining 20% of variance. CONCLUSIONS ESQ symptoms improved during HAz, HA, and HT 2x/week. ESQ symptoms were not statistically correlated with HR during exercise heat stress. TS was not sensitive to detecting adaptation and did not subjectively change. The ESQ may be valuable in monitoring adaptation and may contribute to performance post-acclimation.
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Affiliation(s)
- Ciara N. Manning
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Courteney L. Benjamin
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Department of Kinesiology, Samford University, Birmingham, AL 35226, USA
| | - Yasuki Sekiguchi
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Sports Performance Lab, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79430, USA
| | - Cody R. Butler
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Special Warfare Human Performance Squadron, Lackland Air Force Base, San Antonio, TX 78236, USA
| | - Michael R. Szymanski
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Rebecca L. Stearns
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Lawrence E. Armstrong
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Elaine C. Lee
- Human Performance Lab, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Douglas J. Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
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Draper G, Wright MD, Ishida A, Chesterton P, Portas M, Atkinson G. Do environmental temperatures and altitudes affect physical outputs of elite football athletes in match conditions? A systematic review of the 'real world' studies. SCI MED FOOTBALL 2023; 7:81-92. [PMID: 35068376 DOI: 10.1080/24733938.2022.2033823] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Players involved in the various football codes compete throughout the calendar year around the world. Therefore, environmental stressors such as temperature and altitude should be considered in preparation for, and during, matches. We aimed to systematically review the observational and quasi-experimental studies that have been specifically designed to quantify the effects of temperature (hot or cold) high altitude on in-match physical performance indicators. A search of electronic databases (Web of Science, Scopus, SPORTDiscus, PubMed/MEDLINE) was conducted, with 19,424 papers identified as relevant. Following sifting in relation to the eligibility criteria, 12 papers were deemed directly relevant. The reviewed studies scored 6-9 (on a 0-9 scale) for quality assessment using a previously used scale. The major outcome variables relevant to the current review were total distance (m), high-speed running (m) and high-speed runs (count) measured during matches. Standardized effect sizes (ES) were heterogeneous across studies for total distance (ES: -0.96 to -0.14) and high-speed running (ES: -0.69 to 0.12) for >1000 m vs sea-level, time spent at the given altitude being a putative factor for this heterogeneity. Heat had mainly detrimental effects on performance, but ES were, again, heterogeneous across studies (ES: -1.25 to 0.26), dependent on temperature. Given the small number of studies that involved mostly male athletes, and large heterogeneity across studies, more research needs be conducted on physical performance in these environmental conditions, with attention paid to standardizing outcomes and broadening the approaches of studies to guide future decision-making in professional sporting environments.
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Affiliation(s)
- Garrison Draper
- School of Health and Life Sciences, Teesside University, Middlesbrough, UK.,Philadelphia Union, Major League Soccer (MLS), Philadelphia, Pennsylvania, USA
| | - Matthew D Wright
- School of Health and Life Sciences, Teesside University, Middlesbrough, UK
| | - Ai Ishida
- Philadelphia Union, Major League Soccer (MLS), Philadelphia, Pennsylvania, USA.,College of Health Sciences and Professions, Ohio University, Athens, Ohio, USA
| | - Paul Chesterton
- School of Health and Life Sciences, Teesside University, Middlesbrough, UK
| | - Matthew Portas
- School of Health and Life Sciences, Teesside University, Middlesbrough, UK
| | - Greg Atkinson
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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Siquier-Coll J, Bartolomé I, Pérez-Quintero M, Toro-Román V, Grijota FJ, Maynar-Mariño M. Heart Rate and Body Temperature Evolution in an Interval Program of Passive Heat Acclimation at High Temperatures (100 ± 2 °C) in a Sauna. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2082. [PMID: 36767447 PMCID: PMC9916041 DOI: 10.3390/ijerph20032082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Heat exposure provokes stress on the human body. If it remains constant, it leads to adaptations such as heat acclimation. This study aims to observe the evolution of heart rate (HR), core temperature (Tcore), and skin temperature (Tskin) in an intervallic program of exposure to extreme heat. Twenty-nine healthy male volunteers were divided into a control group (CG; n = 14) and an experimental group (EG; n = 15). EG experienced nine sessions (S) of intervallic exposure to high temperatures (100 ± 2 °C), whereas CG was exposed to ambient temperatures (22 ± 2 °C). HR, Tskin, and Tcore were monitored in S1, 4, 5, 8, and 9. An important increase in HR occurred in the S4 compared to the rest (p < 0.05) in EG. A lower HR was discovered in S8 and S9 compared to S4 and in S9 in relation to S1 (p < 0.05) in EG. EG experiences a gradual decrease in Tcore and Tskin, which was detected throughout the assessments, although it was only significant in the S8 and S9 (p < 0.05). Interval exposure to heat at 100 ± 2 °C elicits stress on the human organism, fundamentally increasing Tcore, Tskin, and FC. This recurring stress in the full program caused a drop in the thermoregulatory response as an adaptation or acclimation to heat.
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Affiliation(s)
- Jesús Siquier-Coll
- SER Research Group, Center of Higher Education Alberta Giménez, Comillas Pontifical University, Costa de Saragossa 16, 07013 Palma Mallorca, Spain
| | - Ignacio Bartolomé
- Department of Sport Science, Faculty of Education, Pontifical University of Salamanca, C/Henry Collet, 52-70, 37007 Salamanca, Spain
| | - Mario Pérez-Quintero
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Caceres, Spain
| | - Víctor Toro-Román
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Caceres, Spain
| | - Francisco J. Grijota
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Caceres, Spain
| | - Marcos Maynar-Mariño
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Caceres, Spain
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62
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Gordon RJFH, Moss JN, Castelli F, Reeve T, Diss CE, Tyler CJ, Tillin NA. Heat acclimation reduces the effects of whole-body hyperthermia on knee-extensor relaxation rate, but does not affect voluntary torque production. Eur J Appl Physiol 2023; 123:1067-1080. [PMID: 36637508 PMCID: PMC10119217 DOI: 10.1007/s00421-022-05127-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 12/23/2022] [Indexed: 01/14/2023]
Abstract
PURPOSE This study investigated the effects of acute hyperthermia and heat acclimation (HA) on maximal and rapid voluntary torque production, and their neuromuscular determinants. METHODS Ten participants completed 10 days of isothermic HA (50 °C, 50% rh) and had their knee-extensor neuromuscular function assessed in normothermic and hyperthermic conditions, pre-, after 5 and after 10 days of HA. Electrically evoked twitch and octet (300 Hz) contractions were delivered at rest. Maximum voluntary torque (MVT), surface electromyography (EMG) normalised to maximal M-wave, and voluntary activation (VA) were assessed during brief maximal isometric voluntary contractions. Rate of torque development (RTD) and normalised EMG were measured during rapid voluntary contractions. RESULTS Acute hyperthermia reduced neural drive (EMG at MVT and during rapid voluntary contractions; P < 0.05), increased evoked torques (P < 0.05), and shortened contraction and relaxation rates (P < 0.05). HA lowered resting rectal temperature and heart rate after 10 days (P < 0.05), and increased sweating rate after 5 and 10 days (P < 0.05), no differences were observed between 5 and 10 days. The hyperthermia-induced reduction in twitch half-relaxation was attenuated after 5 and 10 days of HA, but there were no other effects on neuromuscular function either in normothermic or hyperthermic conditions. CONCLUSION HA-induced favourable adaptations to the heat after 5 and 10 days of exposure, but there was no measurable benefit on voluntary neuromuscular function in normothermic or hyperthermic conditions. HA did reduce the hyperthermic-induced reduction in twitch half-relaxation time, which may benefit twitch force summation and thus help preserve voluntary torque in hot environmental conditions.
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Affiliation(s)
- Ralph Joseph Frederick Hills Gordon
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK. .,Faculty of Science and Engineering, School of Psychology & Sport Science, Anglia Ruskin University, East Road, Cambridge, CB1 1PT, UK.
| | - Jodie Natasha Moss
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Federico Castelli
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Thomas Reeve
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Ceri Elen Diss
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Christopher James Tyler
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Neale Anthony Tillin
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
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63
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Peel J, John K, Page J, Scott G, Jeffries O, Heffernan S, Tallent J, Waldron M. Factors contributing to the change in thermoneutral maximal oxygen consumption after iso-intensity heat acclimation programmes. Eur J Sport Sci 2023:1-10. [PMID: 36533403 DOI: 10.1080/17461391.2022.2160278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The factors explaining variance in thermoneutral maximal oxygen uptake (V˙O2max) adaptation to heat acclimation (HA) were evaluated, with consideration of HA programme parameters, biophysical variables and thermo-physiological responses. Seventy-one participants consented to perform iso-intensity training (range: 45%-55% V˙O2max) in the heat (range: 30°C-38°C; 20%-60% relative humidity) on consecutive days (range: 5-days-14-days) for between 50-min and-90 min. The participants were evaluated for their thermoneutral V˙O2max change pre-to-post HA. Participants' whole-body sweat rate, heart rate, core temperature, perceived exertion and thermal sensation and plasma volume were measured, and changes in these responses across the programme determined. Partial least squares regression was used to explain variance in the change in V˙O2max across the programme using 24 variables. Sixty-three percent of the participants increased V˙O2max more than the test error, with a mean ± SD improvement of 2.6 ± 7.9%. A two-component model minimised the root mean squared error and explained the greatest variance (R2; 65%) in V˙O2max change. Eight variables positively contributed (P < 0.05) to the model: exercise intensity (%V˙O2max), ambient temperature, HA training days, total exposure time, baseline body mass, thermal sensation, whole-body mass losses and the number of days between the final day of HA and the post-testing day. Within the ranges evaluated, iso-intensity HA improved V˙O2max 63% of the time, with intensity - and volume-based parameters, alongside sufficient delays in post-testing being important considerations for V˙O2max maximisation. Monitoring of thermal sensation and body mass losses during the programme offers an accessible way to gauge the degree of potential adaptation.
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Affiliation(s)
- Jenny Peel
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Kevin John
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Joe Page
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Georgia Scott
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Owen Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Shane Heffernan
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Jamie Tallent
- School of Sport, Rehabilitation, and Exercise Sciences, University of Essex, Colchester, UK.,Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences, School of Primary and Allied Health Care, Monash University, Melbourne, Australia
| | - Mark Waldron
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK.,Welsh Institute of Performance Science, Swansea University, Swansea, UK.,School of Health and Behavioural Sciences, University of the Sunshine Coast, Queensland, Australia
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64
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Shen W, Zhou Q. SPORTS INJURIES IN HIGH-LEVEL AEROBIC GYMNASTICS ATHLETES. REV BRAS MED ESPORTE 2023. [DOI: 10.1590/1517-8692202329012022_0479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
ABSTRACT Introduction: With the rapid development of aerobic gymnastics worldwide, research is required to constantly increase. Objective: Analyze the main causes of sports injuries, proposing measures for prevention, treatment, and rehabilitation, as well as providing a theoretical basis for reducing the risk of sports injuries and actively seeking ways and measures to prevent and treat sports injuries in aerobic gymnastics athletes. Methods: Statistical-mathematical analysis was used, mainly including the coefficient of variation method, correlation matrix method, and factor analysis. The common variable of the trend of sports injuries was found. Results: The research shows that the scientific awareness, self-protection, and injury prevention of aerobic gymnastics training strengthen the ideological education and theoretical guidance of athletes, improve athletes' awareness of sports injuries, regulate technical specifications, strengthen fitness training and improve Chinese competitive aerobics. Conclusion: In the healthy period before injuries, we should take various measures to improve physical fitness and skills, enabling good health work in the acute period after injuries and understanding the working principle of early diagnosis and treatment to better use treatment time. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.
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65
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Takada A, Kodera S, Suzuki K, Nemoto M, Egawa R, Takizawa H, Hirata A. Estimation of the number of heat illness patients in eight metropolitan prefectures of Japan: Correlation with ambient temperature and computed thermophysiological responses. Front Public Health 2023; 11:1061135. [PMID: 36875384 PMCID: PMC9982159 DOI: 10.3389/fpubh.2023.1061135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 01/31/2023] [Indexed: 02/19/2023] Open
Abstract
The number of patients with heat illness transported by ambulance has been gradually increasing due to global warming. In intense heat waves, it is crucial to accurately estimate the number of cases with heat illness for management of medical resources. Ambient temperature is an essential factor with respect to the number of patients with heat illness, although thermophysiological response is a more relevant factor with respect to causing symptoms. In this study, we computed daily maximum core temperature increase and daily total amount of sweating in a test subject using a large-scale, integrated computational method considering the time course of actual ambient conditions as input. The correlation between the number of transported people and their thermophysiological temperature is evaluated in addition to conventional ambient temperature. With the exception of one prefecture, which features a different Köppen climate classification, the number of transported people in the remaining prefectures, with a Köppen climate classification of Cfa, are well estimated using either ambient temperature or computed core temperature increase and daily amount of sweating. For estimation using ambient temperature, an additional two parameters were needed to obtain comparable accuracy. Even using ambient temperature, the number of transported people can be estimated if the parameters are carefully chosen. This finding is practically useful for the management of ambulance allocation on hot days as well as public enlightenment.
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Affiliation(s)
- Akito Takada
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Sachiko Kodera
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Koji Suzuki
- Architecture, Design, Civil Engineering, and Industrial Management Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Mio Nemoto
- Department of Environment Systems, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Ryusuke Egawa
- School of Engineering, Tokyo Denki University, Tokyo, Japan.,Cyberscience Center, Tohoku University, Sendai, Japan
| | | | - Akimasa Hirata
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, Japan
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66
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Racinais S, Hosokawa Y, Akama T, Bermon S, Bigard X, Casa DJ, Grundstein A, Jay O, Massey A, Migliorini S, Mountjoy M, Nikolic N, Pitsiladis YP, Schobersberger W, Steinacker JM, Yamasawa F, Zideman DA, Engebretsen L, Budgett R. IOC consensus statement on recommendations and regulations for sport events in the heat. Br J Sports Med 2023; 57:8-25. [PMID: 36150754 PMCID: PMC9811094 DOI: 10.1136/bjsports-2022-105942] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2022] [Indexed: 01/07/2023]
Abstract
This document presents the recommendations developed by the IOC Medical and Scientific Commission and several international federations (IF) on the protection of athletes competing in the heat. It is based on a working group, meetings, field experience and a Delphi process. The first section presents recommendations for event organisers to monitor environmental conditions before and during an event; to provide sufficient ice, shading and cooling; and to work with the IF to remove regulatory and logistical limitations. The second section summarises recommendations that are directly associated with athletes' behaviours, which include the role and methods for heat acclimation; the management of hydration; and adaptation to the warm-up and clothing. The third section explains the specific medical management of exertional heat stroke (EHS) from the field of play triage to the prehospital management in a dedicated heat deck, complementing the usual medical services. The fourth section provides an example for developing an environmental heat risk analysis for sport competitions across all IFs. In summary, while EHS is one of the leading life-threatening conditions for athletes, it is preventable and treatable with the proper risk mitigation and medical response. The protection of athletes competing in the heat involves the close cooperation of the local organising committee, the national and international federations, the athletes and their entourages and the medical team.
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Affiliation(s)
- Sebastien Racinais
- Research and Scientific Support Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Ad Dawhah, Qatar
| | - Yuri Hosokawa
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Takao Akama
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | | | - Xavier Bigard
- Union Cycliste Internationale (UCI), Aigle, Switzerland
| | - Douglas J Casa
- Korey Stringer Institiute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut, USA
| | - Andrew Grundstein
- Department of Geography, University of Georgia, Athens, Georgia, USA
| | - Ollie Jay
- Heat and Health Research Incubator, Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
| | - Andrew Massey
- Medical Department, Federation Internationale de Football Association, Zurich, Switzerland
| | | | | | | | | | - Wolfgang Schobersberger
- Institute for Sports Medicine, Alpine Medicine & Health Tourism (ISAG), UMIT Tirol – Private University for Health Sciences and technology, Hall, Austria,University Hospital/Tirol Kliniken, Innsbruck, Austria
| | | | | | - David Anthony Zideman
- International Olympic Committee Medical and Scientific Games Group, Pinner, Middlesex, UK
| | - Lars Engebretsen
- Medical and Scientific Department, International Olympic Committee, Lausanne, Switzerland
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67
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Guzman-Echavarria G, Middel A, Vanos J. Beyond heat exposure - new methods to quantify and link personal heat exposure, stress, and strain in diverse populations and climates: The journal Temperature toolbox. Temperature (Austin) 2022; 10:358-378. [PMID: 37554380 PMCID: PMC10405775 DOI: 10.1080/23328940.2022.2149024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/31/2022] [Accepted: 11/12/2022] [Indexed: 11/21/2022] Open
Abstract
Fine-scale personal heat exposure (PHE) information can help prevent or minimize weather-related deaths, illnesses, and reduced work productivity. Common methods to estimate heat risk do not simultaneously account for the intensity, frequency, and duration of thermal exposures, nor do they include inter-individual factors that modify physiological response. This study demonstrates new whole-body net thermal load estimations to link PHE to heat stress and strain over time. We apply a human-environment heat exchange model to examine how time-varying net thermal loads differ across climate contexts, personal attributes, and spatiotemporal scales. First, we investigate summertime climatic PHE impacts for three US cities: Phoenix, Miami, and New York. Second, we model body morphology and acclimatization for three profiles (middle-aged male/female; female >65 years). Finally, we quantify model sensitivity using representative data at synoptic and micro-scales. For all cases, we compare required and potential evaporative heat losses that can lead to dangerous thermal exposures based on (un)compensable heat stress. Results reveal misclassifications in heat stress or strain due to incomplete environmental data and assumed equivalent physiology and activities between people. Heat strain is most poorly represented by PHE alone for the elderly, non-acclimatized, those engaged in strenuous activities, and when negating solar radiation. Moreover, humid versus dry heat across climates elicits distinct thermal responses from the body. We outline criteria for inclusive PHE evaluations connecting heat exposure, stress, and strain while using physiological-based methods to avoid misclassifications. This work underlines the value of moving from "one-size-fits-all" thermal indices to "fit-for-purpose" approaches using personalized information.
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Affiliation(s)
- Gisel Guzman-Echavarria
- School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ, USA
| | - Ariane Middel
- School of Arts, Media and Engineering, Arizona State University, Tempe, AZ, USA
- School of Computing and Augmented Intelligence, Arizona State University,Tempe, AZ, USA
| | - Jennifer Vanos
- School of Sustainability, Arizona State University, Tempe, AZ, USA
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68
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Soligard T, Palmer D, Steffen K, Lopes AD, Grek N, Onishi K, Shimakawa T, Grant ME, Mountjoy M, Budgett R, Engebretsen L. New sports, COVID-19 and the heat: sports injuries and illnesses in the Tokyo 2020 Summer Olympics. Br J Sports Med 2022; 57:bjsports-2022-106155. [PMID: 36588430 DOI: 10.1136/bjsports-2022-106155] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To describe the incidence of injuries and illnesses sustained during the Tokyo Summer Olympic Games from 23 July to 8 August 2021. METHODS We recorded the daily number of athlete injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the Tokyo 2020 medical staff. RESULTS In total, 11 315 athletes (5423 women, 48%; 5892 men, 52%) from 206 NOCs were followed up prospectively for the occurrence of injury and illness. NOC and Tokyo 2020 medical staff reported 1035 injuries and 438 illnesses, equalling 9.1 injuries and 3.9 illnesses per 100 athletes over the 17-day period. Altogether, 9% of the athletes incurred at least one injury and 4% at least one illness. The incidence of injury was highest in boxing (27%), BMX racing (27%), BMX freestyle (22%), skateboarding (21%), karate (19%) and handball (18%), of which both BMX freestyle and skateboarding were new events, and lowest in diving, road cycling, rowing, marathon swimming and shooting (1-2%). Marathon and artistic swimming presented the highest illness incidences (both 8%), followed by skateboarding and karate (both 7%). In the study period, COVID-19 affected 18 athletes, accounting for 4% of all illnesses and 0.16% of all athletes. Exertional heat illness affected 78 athletes (18% of all illnesses, 0.7% of all athletes), the majority (88%) resulting in no time lost from sport. CONCLUSION Overall, 9% of the athletes incurred an injury and 4% an illness during the Games. Comprehensive countermeasures helped mitigate both COVID-19 and exertional heat illnesses.
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Affiliation(s)
- Torbjørn Soligard
- Medical and Scientific Department, International Olympic Committee, Lausanne, Switzerland
| | - Debbie Palmer
- Edinburgh Sports Medicine Research Network, University of Edinburgh Institute for Sport Physical Education and Health Sciences, Edinburgh, UK
- Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK
| | - Kathrin Steffen
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo Sports Trauma Research Center, Oslo, Norway
| | - Alexandre Dias Lopes
- Department of Physical Therapy, Movement and Rehabilitation Sciences, Northeastern University, Boston, Massachusetts, USA
| | | | - Kentaro Onishi
- Department of Physical Medicine and Rehabilitation, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Tomoyuki Shimakawa
- Department of Orthopaedic Surgery, Yaesekai Doujin Hospital, Okinawa, Japan
| | - Marie-Elaine Grant
- Institute of Sport and Health, University College Dublin, Dublin, Ireland
| | - Margo Mountjoy
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Richard Budgett
- Medical and Scientific Department, International Olympic Committee, Lausanne, Switzerland
| | - Lars Engebretsen
- Medical and Scientific Department, International Olympic Committee, Lausanne, Switzerland
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo Sports Trauma Research Center, Oslo, Norway
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69
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Pawłowska M, Mila-Kierzenkowska C, Boraczyński T, Boraczyński M, Szewczyk-Golec K, Sutkowy P, Wesołowski R, Budek M, Woźniak A. The Influence of Ambient Temperature Changes on the Indicators of Inflammation and Oxidative Damage in Blood after Submaximal Exercise. Antioxidants (Basel) 2022; 11:2445. [PMID: 36552653 PMCID: PMC9774713 DOI: 10.3390/antiox11122445] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Physical activity has a positive effect on human health and well-being, but intense exercise can cause adverse changes in the organism, leading to the development of oxidative stress and inflammation. The aim of the study was to determine the effect of short-term cold water immersion (CWI) and a sauna bath as methods of postexercise regeneration on the indicators of inflammation and oxidative damage in the blood of healthy recreational athletes. Forty-five male volunteers divided into two groups: 'winter swimmers' who regularly use winter baths (n = 22, average age 43.2 ± 5.9 years) and 'novices' who had not used winter baths regularly before (n = 23, mean age 25 ± 4.8 years) participated in the study. The research was divided into two experiments, differing in the method of postexercise regeneration used, CWI (Experiment I) and a sauna bath (Experiment II). During Experiment I, the volunteers were subjected to a 30-min aerobic exercise, combined with a 20-min rest at room temperature (RT-REST) or a 20-min rest at room temperature with an initial 3-min 8 °C water bath (CWI-REST). During the Experiment II, the volunteers were subjected to the same aerobic exercise, followed by a RT-REST or a sauna bath (SAUNA-REST). The blood samples were taken before physical exercise (control), immediately after exercise and 20 min after completion of regeneration. The concentrations of selected indicators of inflammation, including interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 8 (IL-8), interleukin 10 (IL-10), transforming growth factor β1 (TGF-β1) and tumor necrosis factor α (TNF-α), as well as the activity of indicators of oxidative damage: α1-antitrypsin (AAT) and lysosomal enzymes, including arylsulfatase A (ASA), acid phosphatase (AcP) and cathepsin D (CTS D), were determined. CWI seems to be a more effective post-exercise regeneration method to reduce the inflammatory response compared to a sauna bath. A single sauna bath is associated with the risk of proteolytic tissue damage, but disturbances of cellular homeostasis are less pronounced in people who regularly use cold water baths than in those who are not adapted to thermal stress.
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Affiliation(s)
- Marta Pawłowska
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Celestyna Mila-Kierzenkowska
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Tomasz Boraczyński
- Department of Health Sciences, Olsztyn University College, 10-283 Olsztyn, Poland
| | - Michał Boraczyński
- Department of Health Sciences, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland
| | - Karolina Szewczyk-Golec
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Paweł Sutkowy
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Roland Wesołowski
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Marlena Budek
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
| | - Alina Woźniak
- Department of Medical Biology and Biochemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
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70
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Individual variability in achievement of short-term heat acclimation during a fixed intensity protocol. J Therm Biol 2022; 110:103373. [DOI: 10.1016/j.jtherbio.2022.103373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 10/04/2022] [Accepted: 10/12/2022] [Indexed: 12/05/2022]
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71
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Jacobsen AP, Khiew YC, Duffy E, O'Connell J, Brown E, Auwaerter PG, Blumenthal RS, Schwartz BS, McEvoy JW. Climate change and the prevention of cardiovascular disease. Am J Prev Cardiol 2022; 12:100391. [PMID: 36164332 PMCID: PMC9508346 DOI: 10.1016/j.ajpc.2022.100391] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/27/2022] [Accepted: 09/10/2022] [Indexed: 11/26/2022] Open
Abstract
Climate change is a worsening global crisis that will continue negatively impacting population health and well-being unless adaptation and mitigation interventions are rapidly implemented. Climate change-related cardiovascular disease is mediated by air pollution, increased ambient temperatures, vector-borne disease and mental health disorders. Climate change-related cardiovascular disease can be modulated by climate change adaptation; however, this process could result in significant health inequity because persons and populations of lower socioeconomic status have fewer adaptation options. Clear scientific evidence for climate change and its impact on human health have not yet resulted in the national and international impetus and policies necessary to slow climate change. As respected members of society who regularly communicate scientific evidence to patients, clinicians are well-positioned to advocate on the importance of addressing climate change. This narrative review summarizes the links between climate change and cardiovascular health, proposes actionable items clinicians and other healthcare providers can execute both in their personal life and as an advocate of climate policies, and encourages communication of the health impacts of climate change when counseling patients. Our aim is to inspire the reader to invest more time in communicating the most crucial public health issue of the 21st century to their patients.
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Affiliation(s)
- Alan P. Jacobsen
- Ciccarone Center for the Prevention of Cardiovascular Disease, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Yii Chun Khiew
- Division of Gastroenterology, Department of Gastroenterology, MedStar Georgetown University Hospital, Washington, DC, United States
| | - Eamon Duffy
- Division of Cardiology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - James O'Connell
- Department of Public Health, Health Service Executive West, Galway, Ireland
| | - Evans Brown
- Department of Medicine, Division of Hospital Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Paul G. Auwaerter
- Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Roger S. Blumenthal
- Ciccarone Center for the Prevention of Cardiovascular Disease, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Brian S. Schwartz
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - John William McEvoy
- Ciccarone Center for the Prevention of Cardiovascular Disease, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- National Institute for Prevention and Cardiovascular Health, National University of Ireland Galway, Galway, Ireland
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Effects of Elevated Body Temperature on Selected Physiological Indices and Thermal Stress in Athletes and Non-Athletes. J Hum Kinet 2022; 84:112-123. [DOI: 10.2478/hukin-2021-0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Abstract
The purpose of this study was to determine the effects of active and passive overheating. A group of athletes (A) and non-athletic men (N) underwent an exercise stress test at elevated ambient temperature and sauna bathing until an increase in rectal temperature of 1.2°C was observed. It was shown that group A performed physical exercise for a longer period of time, which elicited significantly higher amounts of work performed in the stress test. Both forms of overheating caused a significant decrease in BM and a significant change in plasma volume, while greater dehydration was observed after active overheating. Changes observed in group A were higher than in group N. MCV levels were initially higher in group A. The levels in both groups decreased after sauna bathing, although in non-athletes the decrease was greater. Both forms of overheating increased Hb, HCT, and SBP, while only the non-athletic group showed a decrease in DBP after the exercise stress test. However, a decrease in DBP was observed in both groups after sauna bathing. The PSI increased after both tests, yet to a higher extent after the stress test than after sauna bathing. The PSI was negatively correlated with VO2max in both groups. The increase in cortisol concentration was higher after sauna bathing. There was a correlation between cortisol levels and the work performed during the stress test in group A. Endurance training resulted in more efficient thermoregulatory mechanisms in athletes.
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Sekiguchi Y, Benjamin CL, Manning CN, Butler CR, Szymanski MR, Filep EM, Stearns RL, Distefano LJ, Lee EC, Casa DJ. Using Predictive Modeling Technique to Assess Core Temperature Adaptations from Heart Rate, Sweat Rate, and Thermal Sensation in Heat Acclimatization and Heat Acclimation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:13009. [PMID: 36293588 PMCID: PMC9602154 DOI: 10.3390/ijerph192013009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/29/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Assessing the adaptation of rectal temperature (Trec) is critical following heat acclimatization (HAz) and heat acclimation (HA) because it is associated with exercise performance and safety; however, more feasible and valid methods need to be identified. The purpose of this study was to predict adaptations in Trec from heart rate (HR), sweat rate (SR), and thermal sensation (TS) using predictive modeling techniques. Twenty-five male endurance athletes (age, 36 ± 12 y; VO2max, 57.5 ± 7.0 mL⋅kg-1⋅min-1) completed three trials consisting of 60 min running at 59.3 ± 1.7% vVO2max in a hot environment. During trials, the highest HR and TS, SR, and Trec at the end of trials were recorded. Following a baseline trial, participants performed HAz followed by a post-HAz trial and then completed five days HA, followed by a post-HA trial. A decision tree indicated cut-points of HR (<-13 bpm), SR (>0.3 L·h-1), and TS (≤-0.5) to predict lower Trec. When two or three variables met cut-points, the probability of accuracy of showing lower Trec was 95.7%. Greater adaptations in Trec were observed when two or three variables met cut-points (-0.71 ± 0.50 °C) compared to one (-0.13 ± 0.36 °C, p < 0.001) or zero (0.0 3 ± 0.38 °C, p < 0.001). Specificity was 0.96 when two or three variables met cut-points to predict lower Trec. These results suggest using heart rate, sweat rate, and thermal sensation adaptations to indicate that the adaptations in Trec is beneficial following heat adaptations, especially in field settings, as a practical and noninvasive method.
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Affiliation(s)
- Yasuki Sekiguchi
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, 3204 Main Street, Lubbock, TX 79409, USA
| | - Courteney L. Benjamin
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Department of Kinesiology, Samford University, Birmingham, AL 35229, USA
| | - Ciara N. Manning
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Cody R. Butler
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Michael R. Szymanski
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Erica M. Filep
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
- Department of Kinesiology and Military Science, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412, USA
| | - Rebecca L. Stearns
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Lindsay J. Distefano
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Elaine C. Lee
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Douglas J. Casa
- Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
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74
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Weller RS, Buono MJ. The effect of heat acclimation on the sweat lactate concentration vs. sweat rate relationship. J Therm Biol 2022; 109:103325. [DOI: 10.1016/j.jtherbio.2022.103325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 07/21/2022] [Accepted: 08/31/2022] [Indexed: 10/14/2022]
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Murray KO, Clanton TL, Horowitz M. Epigenetic responses to heat: From adaptation to maladaptation. Exp Physiol 2022; 107:1144-1158. [PMID: 35413138 PMCID: PMC9529784 DOI: 10.1113/ep090143] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/25/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? This review outlines the history of research on epigenetic adaptations to heat exposure. The perspective taken is that adaptations reflect properties of hormesis, whereby low, repeated doses of heat induce adaptation (acclimation/acclimatization); whereas brief, life-threatening exposures can induce maladaptive responses. What advances does it highlight? The epigenetic mechanisms underlying acclimation/acclimatization comprise specific molecular programmes on histones that regulate heat shock proteins transcriptionally and protect the organism from subsequent heat exposures, even after long delays. The epigenetic signalling underlying maladaptive responses might rely, in part, on extensive changes in DNA methylation that are sustained over time and might contribute to later health challenges. ABSTRACT Epigenetics plays a strong role in molecular adaptations to heat by producing a molecular memory of past environmental exposures. Moderate heat, over long periods of time, induces an 'adaptive' epigenetic memory, resulting in a condition of 'resilience' to future heat exposures or cross-tolerance to other forms of toxic stress. In contrast, intense, life-threatening heat exposures, such as severe heat stroke, can result in a 'maladaptive' epigenetic memory that can place an organism at risk of later health complications. These cellular memories are coded by post-translational modifications of histones on the nucleosomes and/or by changes in DNA methylation. They operate by inducing changes in the level of gene transcription and therefore phenotype. The adaptive response to heat acclimation functions, in part, by facilitating transcription of essential heat shock proteins and exhibits a biphasic short programme (maintaining DNA integrity, followed by a long-term consolidation). The latter accelerates acclimation responses after de-acclimation. Although less studied, the maladaptive responses to heat stroke appear to be coded in long-lasting changes in DNA methylation near the promoter region of genes involved with basic cell function. Whether these memories are also encoded in histone modifications is not yet known. There is considerable evidence that both adaptive and maladaptive epigenetic responses to heat can be inherited, although most evidence comes from lower organisms. Future challenges include understanding the signalling mechanisms responsible and discovering new ways to promote adaptive responses while suppressing maladaptive responses to heat, as all life forms adapt to life on a warming planet.
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Affiliation(s)
- Kevin O. Murray
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Thomas L. Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Michal Horowitz
- Laboratory of Environmental Physiology, Faculty of Dentistry, The Hebrew University of Jerusalem, Jerusalem, Israel
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76
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Périard JD, DeGroot D, Jay O. Exertional heat stroke in sport and the military: epidemiology and mitigation. Exp Physiol 2022; 107:1111-1121. [PMID: 36039024 PMCID: PMC9826288 DOI: 10.1113/ep090686] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/12/2022] [Indexed: 01/11/2023]
Abstract
NEW FINDINGS What is the topic of this review? Exertional heat stroke epidemiology in sport and military settings, along with common risk factors and strategies and policies designed to mitigate its occurrence. What advances does it highlight? Individual susceptibility to exertional heat stroke risk is dependent on the interaction of intrinsic and extrinsic factors. Heat policies in sport should assess environmental conditions, as well as the characteristics of the athlete, clothing/equipment worn and activity level of the sport. Exertional heat stroke risk reduction in the military should account for factors specific to training and personnel. ABSTRACT Exertional heat illness occurs along a continuum, developing from the relatively mild condition of muscle cramps, to heat exhaustion, and in some cases to the life-threatening condition of heat stroke. The development of exertional heat stroke (EHS) is associated with an increase in core temperature stemming from inadequate heat dissipation to offset the rate of metabolically generated heat. Susceptibility to EHS is linked to the interaction of several factors including environmental conditions, individual characteristics, health conditions, medication and drug use, behavioural responses, and sport/organisational requirements. Two settings in which EHS is commonly observed are competitive sport and the military. In sport, the exact prevalence of EHS is unclear due to inconsistent exertional heat illness terminology, diagnostic criteria and data reporting. In contrast, exertional heat illness surveillance in the military is facilitated by standardised case definitions, a requirement to report all heat illness cases and a centralised medical record repository. To mitigate EHS risk, several strategies can be implemented by athletes and military personnel, including heat acclimation, ensuring adequate hydration, cold-water immersion and mandated work-to-rest ratios. Organisations may also consider developing sport or military task-specific heat stress policies that account for the evaporative heat loss requirement of participants, relative to the evaporative capacity of the environment. This review examines the epidemiology of EHS along with the strategies and policies designed to reduce its occurrence in sport and military settings. We highlight the nuances of identifying individuals at risk of EHS and summarise the benefits and shortcomings of various mitigation strategies.
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Affiliation(s)
- Julien D. Périard
- Research Institute for Sport and ExerciseUniversity of CanberraCanberraAustralia
| | - David DeGroot
- Army Heat CenterMartin Army Community HospitalFort BenningGAUSA
| | - Ollie Jay
- Thermal Ergonomics LaboratoryHeat and Health Research IncubatorFaculty of Medicine and HealthUniversity of SydneyCamperdownAustralia
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77
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Cramer MN, Gagnon D, Laitano O, Crandall CG. Human temperature regulation under heat stress in health, disease, and injury. Physiol Rev 2022; 102:1907-1989. [PMID: 35679471 PMCID: PMC9394784 DOI: 10.1152/physrev.00047.2021] [Citation(s) in RCA: 65] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 05/10/2022] [Accepted: 05/28/2022] [Indexed: 12/30/2022] Open
Abstract
The human body constantly exchanges heat with the environment. Temperature regulation is a homeostatic feedback control system that ensures deep body temperature is maintained within narrow limits despite wide variations in environmental conditions and activity-related elevations in metabolic heat production. Extensive research has been performed to study the physiological regulation of deep body temperature. This review focuses on healthy and disordered human temperature regulation during heat stress. Central to this discussion is the notion that various morphological features, intrinsic factors, diseases, and injuries independently and interactively influence deep body temperature during exercise and/or exposure to hot ambient temperatures. The first sections review fundamental aspects of the human heat stress response, including the biophysical principles governing heat balance and the autonomic control of heat loss thermoeffectors. Next, we discuss the effects of different intrinsic factors (morphology, heat adaptation, biological sex, and age), diseases (neurological, cardiovascular, metabolic, and genetic), and injuries (spinal cord injury, deep burns, and heat stroke), with emphasis on the mechanisms by which these factors enhance or disturb the regulation of deep body temperature during heat stress. We conclude with key unanswered questions in this field of research.
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Affiliation(s)
- Matthew N Cramer
- Defence Research and Development Canada-Toronto Research Centre, Toronto, Ontario, Canada
| | - Daniel Gagnon
- Montreal Heart Institute and School of Kinesiology and Exercise Science, Université de Montréal, Montréal, Quebec, Canada
| | - Orlando Laitano
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
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78
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Osborne JO, Minett GM, Stewart IB, Trost S, Drovandi C, Costello JT, Pavey TG, Borg DN. Evidence that heat acclimation training may alter sleep and incidental activity. Eur J Sport Sci 2022:1-10. [PMID: 36106465 DOI: 10.1080/17461391.2022.2124386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This randomized cross-over study tested the hypothesis that heat acclimation training would detrimentally affect sleep variables and alter incidental physical activity compared to a thermoneutral training control condition. Eight recreationally trained males (V̇O2peak 49±4.9 mL.kg-1.min-1) completed two separate interventions separated by at least 31 days: 5 consecutive day training blocks of moderate-intensity cycling (60 min·day-1 at 50% peak power output) in a hot (34.9±0.7 °C and 53±4 % relative humidity) and a temperate (22.2±2.6 °C; 65±8 % relative humidity) environment. Wrist-mounted accelerometers were worn continuously for the length of the training blocks and recorded physical activity, sleep quality and quantity. Data were analysed in a Bayesian framework, with the results presented as the posterior probability that a coefficient was greater or less than zero. Compared to the temperate training environment, heat acclimation impaired sleep efficiency (Pr β<0 = .979) and wake on sleep onset (Pr β>0 = .917). Daily sedentary time was, on average, 35 min longer (Pr β>0 = .973) and light physical activity time 18 min shorter (Pr β>0 = .960) during the heat acclimation period. No differences were observed between conditions in sleep duration, subjective sleep quality, or moderate or vigorous physical activity. These findings may suggest that athletes and coaches need to be cognisant that heat acclimation training may alter sleep quality and increase sedentary behaviour.HighlightsFive consecutive days of heat training negatively affected some objective measures of sleep quality and incidental physical activity in recreationally trained athletes.Athletes and coaches need to be aware of the potential unintended consequences of using heat acclimation on sleep behaviours.
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Affiliation(s)
- John O Osborne
- School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - Geoffrey M Minett
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - Ian B Stewart
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - Stewart Trost
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
| | - Christopher Drovandi
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- Centre for Data Science, Queensland University of Technology, Brisbane, Australia
| | - Joseph T Costello
- Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, United Kingdom
| | - Toby G Pavey
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia
| | - David N Borg
- Australian Centre for Health Services Innovation and Centre for Healthcare Transformation, School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
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Flunker JC, Zuidema C, Jung J, Kasner E, Cohen M, Seto E, Austin E, Spector JT. Potential Impacts of Different Occupational Outdoor Heat Exposure Thresholds among Washington State Crop and Construction Workers and Implications for Other Jurisdictions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11583. [PMID: 36141863 PMCID: PMC9517246 DOI: 10.3390/ijerph191811583] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 06/10/2023]
Abstract
Occupational heat exposure is associated with substantial morbidity and mortality among outdoor workers. We sought to descriptively evaluate spatiotemporal variability in heat threshold exceedances and describe potential impacts of these exposures for crop and construction workers. We also present general considerations for approaching heat policy-relevant analyses. We analyzed county-level 2011-2020 monthly employment (Bureau of Labor Statistics Quarterly Census of Employment and Wages) and environmental exposure (Parameter-elevation Relationships on Independent Slopes Model (PRISM)) data for Washington State (WA), USA, crop (North American Industry Classification System (NAICS) 111 and 1151) and construction (NAICS 23) sectors. Days exceeding maximum daily temperature thresholds, averaged per county, were linked with employment estimates to generate employment days of exceedances. We found spatiotemporal variability in WA temperature threshold exceedances and crop and construction employment. Maximum temperature exceedances peaked in July and August and were most numerous in Central WA counties. Counties with high employment and/or high numbers of threshold exceedance days, led by Yakima and King Counties, experienced the greatest total employment days of exceedances. Crop employment contributed to the largest proportion of total state-wide employment days of exceedances with Central WA counties experiencing the greatest potential workforce burden of exposure. Considerations from this analysis can help inform decision-making regarding thresholds, timing of provisions for heat rules, and tailoring of best practices in different industries and areas.
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Affiliation(s)
- John C. Flunker
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Christopher Zuidema
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Jihoon Jung
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Edward Kasner
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Martin Cohen
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Edmund Seto
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - Elena Austin
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
| | - June T. Spector
- Department of Environmental and Occupational Health Sciences, Hans Rosling Center for Population Health, University of Washington, Seattle, WA 98195, USA
- Safety & Health Assessment and Research for Prevention (SHARP) Program, Washington State Department of Labor and Industries, Olympia, WA 98504, USA
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80
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Incidence, risk factors, characteristics and prognosis of exertional heat stroke and heat exhaustion in Reunion Island, 2014–2018: A retrospective multicentre study. Sci Sports 2022. [DOI: 10.1016/j.scispo.2021.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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81
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Philp CP, Pitchford NW, Visentin DC, Kitic CM, Fell JW, Buchheit M, Minson CT, Gregory JR, Watson G. Can ten days of heat acclimation training improve temperate-condition rowing performance in national-level rowers? PLoS One 2022; 17:e0273909. [PMID: 36048867 PMCID: PMC9436058 DOI: 10.1371/journal.pone.0273909] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/18/2022] [Indexed: 11/19/2022] Open
Abstract
This study investigated whether heat acclimation (HA) could improve rowing performance in temperate conditions in national-level rowers. Using a parallel-group design, eleven rowers (3 female, 8 male, age: 21±3 years, height: 182.3±6.8cm, mass: 79.2±9.0kg, V˙O2peak: 61.4±5.1ml·kg·min-1) completed either a HA intervention (HEAT, n = 5) or acted as controls (CON, n = 6). The intervention replaced usual cross-training sessions and consisted of an hour of submaximal cycling or rowing ergometry in either 34±0°C for HEAT or 14±1°C for CON daily over two five-day blocks (10 sessions total), separated by 72h. Participants performed the ‘10+4’ test that consists of 10-min submaximal rowing and a 4-min time-trial (TT) in temperate conditions (20±0°C) before and after the intervention. Heat acclimation following the 10-session intervention was evidenced by large significant (p<0.05) decreases in maximum tympanic temperature (d = -1.68) and rate of perceived exertion (RPE) (d = -2.26), and a large significant increase in sweat loss (d = 0.91). Large non-significant (p>0.05) decreases were seen in average tympanic temperature (d = -3.08) and average heart rate (d = -1.53) in HEAT from session 2 to session 10 of the intervention. Furthermore, a large significant increase was seen in plasma volume (d = 3.74), with large significant decreases in haemoglobin concentration (d = -1.78) and hematocrit (d = -12.9). Following the intervention, large non-significant increases in respiratory exchange ratio (d = 0.87) and blood lactate (d = 1.40) as well as a large non-significant decrease in RPE (d = -1.23) were seen in HEAT during the 10-min submaximal rowing. A large significant decrease in peak heart rate (d = -2.27), as well as a large non-significant decrease in relative V˙O2peak (d = -0.90) and large non-significant increases in respiratory exchange ratio (d = 1.18), blood lactate concentration (d = 1.25) and power output (d = 0.96) were seen in HEAT during the 4-min TT. This study suggests that a 10-session HA intervention may elicit HA in national-level rowers, with potential to improve 4-min TT performance in temperate conditions.
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Affiliation(s)
- Calvin P. Philp
- Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Launceston, Tasmania, Australia
- * E-mail:
| | - Nathan W. Pitchford
- Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Launceston, Tasmania, Australia
| | - Denis C. Visentin
- Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Launceston, Tasmania, Australia
| | - Cecilia M. Kitic
- School of Health, Medical and Applied Sciences, Central Queensland University, Brisbane, Queensland, Australia
| | - James W. Fell
- Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Launceston, Tasmania, Australia
| | - Martin Buchheit
- French National Institute of Sport (INSEP), Laboratory of Sport, Expertise and Performance (EA 7370), Paris, France
- Institute for Health & Sport, Victoria University, Melbourne, VIC, Australia
- HIIT Science, Revelstoke, BC, Canada
- Kitman Labs, Performance Research Intelligence Initiative, Dublin, Ireland
| | - Christopher T. Minson
- Department of Human Physiology, University of Oregon, Eugene, Oregon, United States of America
| | - John R. Gregory
- Sports Performance Unit, Tasmanian Institute of Sport, Launceston, Tasmania, Australia
| | - Greig Watson
- Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Launceston, Tasmania, Australia
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Fenemor S, Mills B, Sella F, Gill N, Driller M, Black K, Casadio J, Beaven C. Evaluation of an off-feet heat response test for elite rugby sevens athletes. Sci Sports 2022. [DOI: 10.1016/j.scispo.2021.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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83
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Morrison SA. Moving in a hotter world: Maintaining adequate childhood fitness as a climate change countermeasure. Temperature (Austin) 2022; 10:179-197. [PMID: 37332309 PMCID: PMC10274554 DOI: 10.1080/23328940.2022.2102375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 07/09/2022] [Accepted: 07/12/2022] [Indexed: 10/16/2022] Open
Abstract
Children cope with high temperatures differently than adults do, largely because of slight alterations in their body proportions and heat loss mechanisms compared to fully mature humans. Paradoxically, all current tools of assessing thermal strain have been developed on adults. As the Earth's warming continues to accelerate, children are set to bear the health risk brunt of rising global temperatures. Physical fitness has a direct impact on heat tolerance, yet children are less fit and more obese than ever before. Longitudinal research reveals that children have 30% lower aerobic fitness than their parents did at the same age; this deficit is greater than can be recovered by training alone. So, as the planet's climate and weather patterns become more extreme, children may become less capable of tolerating it. This comprehensive review provides an outline of child thermoregulation and assessment of thermal strain, before moving to summarize how aerobic fitness can modulate hyperthermia, heat tolerance, and behavioral thermoregulation in this under-researched population. The nature of child physical activity, physical fitness, and one's physical literacy journey as an interconnected paradigm for promoting climate change resilience is explored. Finally, future research foci are suggested to encourage continued exploration of this dynamic field, notable since more extreme, multifactorial environmental stressors are expected to continue challenging the physiological strain of the human population for the foreseeable future.
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84
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Tometz MJ, Jevas SA, Esposito PM, Annaccone AR. Validation of Internal and External Load Metrics in NCAA D1 Women's Beach Volleyball. J Strength Cond Res 2022; 36:2223-2229. [PMID: 35916748 DOI: 10.1519/jsc.0000000000003963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
ABSTRACT Tometz, MJ, Jevas, SA, Esposito, PM, and Annaccone, AR. Validation of internal and external load metrics in NCAA D1 women's beach volleyball. J Strength Cond Res 36(8): 2223-2229, 2022-The purpose of this study was to determine the validity of internal and external load metrics in NCAA D1 women's beach volleyball. Subjects included 13 NCAA D1 women's beach volleyball players (age: 20.3 ± 1.4 years). A total of 578 data points were analyzed from 51 team training sessions, including practice, games, and sport-specific conditioning during the pre-season semester (15 weeks). Data points included Edward's training impulse (TRIMP) (228.0 ± 80.7 arbitrary units [AU]), session rating of perceived exertion (sRPE) Load (532.5 ± 232.8 [AU]), distance covered (DC) in meters (2,635.4 ± 884.3 [m]), and daily environmental condition variables {(temperature (76.5 ± 13.7 [°F]), relative humidity (72.5 ± 13.2 [%]), and wet-bulb globe temperature (52.9 ± 19.9 [°F])}. The subjects wore Polar Team Pro heart rate monitors with global positioning system during each session. Subjects completed an sRPE questionnaire after every session. Pearson product moment correlations yielded statistically significant relationships (p < 0.01) between TRIMP and sRPE Load (r = 0.81), TRIMP and DC (r = 0.78), and sRPE Load and DC (r = 0.82). A forward selection multiple regression yielded that sRPE Load could predict TRIMP with the equation: TRIMPTometz = 78.735 + (sRPE Load * 0.28) (p < 0.001). These findings support sRPE Load as a valid alternative to TRIMP when monitoring internal loads in NCAA D1 women's beach volleyball. Session rating of perceived exertion Load may be more practical and accessible for teams. Distance covered should be considered when periodizing and monitoring training loads because of its relationship with internal loads.
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Affiliation(s)
- Matthew J Tometz
- Department of Kinesiology, Texas Christian University, Fort Worth, Texas; and
| | - Stephanie A Jevas
- Department of Kinesiology, Texas Christian University, Fort Worth, Texas; and
| | - Philip M Esposito
- Department of Kinesiology, Texas Christian University, Fort Worth, Texas; and
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85
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Natur S, Damri O, Agam G. The Effect of Global Warming on Complex Disorders (Mental Disorders, Primary Hypertension, and Type 2 Diabetes). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159398. [PMID: 35954764 PMCID: PMC9368177 DOI: 10.3390/ijerph19159398] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 01/09/2023]
Abstract
Multiple studies imply a strong relationship between global warming (GW) and complex disorders. This review summarizes such reports concentrating on three disorders-mental disorders (MD), primary hypertension, and type 2 diabetes (T2D). We also attempt to point at potential mechanisms mediating the effect of GW on these disorders. Concerning mental disorders, immediate candidates are brain levels of heat-shock proteins (HSPs). In addition, given that heat stress increases reactive oxygen species (ROS) levels which may lead to blood-brain barrier (BBB) breakdown and, hence, enhanced protein extravasation in the brain, this might finally cause, or exacerbate mental health. As for hypertension, since its causes are incompletely understood, the mechanism(s) by which heat exposure affects blood pressure (BP) is an open question. Since the kidneys participate in regulating blood volume and BP they are considered as a site of heat-associated disease, hence, we discuss hyperosmolarity as a potential mediator. In addition, we relate to autoimmunity, inflammation, sodium excretion, and HSP70 as risk factors that might play a role in the effect of heat on hypertension. In the case of T2D, we raise two potential mediators of the effect of exposure to ambient hot environment on the disease's incidence-brown adipose tissue metabolism and HSPs.
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86
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Rahman MJ, Parvez SM, Rahman M, He FJ, Cunningham SA, Narayan KMV, Abedin J, Naser AM. Urinary Sodium Excretion and Obesity Markers among Bangladeshi Adult Population: Pooled Data from Three Cohort Studies. Nutrients 2022; 14:3000. [PMID: 35889957 PMCID: PMC9323227 DOI: 10.3390/nu14143000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/05/2022] [Accepted: 07/13/2022] [Indexed: 11/16/2022] Open
Abstract
We evaluated the relationship of urinary sodium excretion with a conditional mean, 10th and 90th percentiles of body mass index (BMI), and waist circumference among 10,034 person-visits of Bangladeshi population. We fitted linear mixed models with participant-level random intercept and restricted maximum likelihood estimation for conditional mean models; and quantile mixed-effect models with participant-level random intercept and Laplace estimation for 10th and 90th percentiles models. For each 100 mmol/24 h increase in urinary sodium excretion, participants had a 0.10 kg/m2 (95% CI: 0.00, 0.10) increase in the mean; a 0.39 kg/m2 (95% CI: 0.23, 0.54) increase in the 10th percentile; and a 0.59 kg/m2 (95% CI: 0.39, 0.78) increase in the 90th percentile of BMI. For each 100 mmol/24 h increase in urinary sodium excretion, participants had a 0.20 cm (95% CI: 0.10, 0.30) increase in mean; a 0.18 cm (95% CI: -0.03, 0.40) change in the 10th percentile; and a 0.23 cm (95% CI: 0.03, 0.43) increase in the 90th percentile of waist circumference. We found a modest association between urine sodium and conditional mean of BMI and waist circumference. The magnitude of associations between urine sodium and the 10th and 90th percentile BMI distributions were higher compared to the conditional mean models, suggesting high sodium intake could be more detrimental to underweight and obese participants.
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Affiliation(s)
- Musarrat J. Rahman
- International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA;
| | - Sarker M. Parvez
- Environmental Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka 1212, Bangladesh; (S.M.P.); (M.R.)
| | - Mahbubur Rahman
- Environmental Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka 1212, Bangladesh; (S.M.P.); (M.R.)
| | - Feng J. He
- Centre for Public Health and Policy, Wolfson Institute of Population Health, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK;
| | - Solveig A. Cunningham
- Emory Global Diabetes Research Center, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA; (S.A.C.); (K.M.V.N.)
| | - K. M. Venkat Narayan
- Emory Global Diabetes Research Center, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA; (S.A.C.); (K.M.V.N.)
| | - Jaynal Abedin
- Data Science Institute, National University of Ireland Galway, H91 TK33 Galway, Ireland;
| | - Abu Mohd Naser
- Division of Epidemiology, Biostatistics and Environmental Health, School of Public Health, University of Memphis, Memphis, TN 38152, USA
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Goto H, Nakashima M, Nakashima H, Noguchi M, Imakiire T, Oshima N, Kinoshita M, Kumagai H. Heat acclimation ameliorated heat stress-induced acute kidney injury and prevented changes in kidney macrophages and fibrosis. Am J Physiol Renal Physiol 2022; 323:F243-F254. [PMID: 35796461 PMCID: PMC9394728 DOI: 10.1152/ajprenal.00065.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heatstroke can cause acute kidney injury (AKI), which reportedly progresses to chronic kidney disease. Kidney macrophages may be involved in such injury. Although heat acclimation (HA) provides thermal resilience, its renoprotective effect and mechanism remain unclear. To investigate heat stress-induced kidney injuries in mice and the mitigating effect of HA on them, male C57/BL6J mice were exposed to heat stress (40℃, 1 h), with or without 5-day HA (38℃, 3 h/day) prior to heat stress. Heat stress damaged kidney proximal tubules with elevation of urinary kidney injury molecule-1 (KIM-1). Kidney fibrosis was observed on day 7 and correlated with the urinary KIM-1 levels on day 3. Kidney resident macrophages decreased on day 1, whereas the number of infiltrating macrophages in the kidney did not change. Both subsets of macrophages polarized to the pro-inflammatory M1 phenotype on day 1; however, they polarized to the anti-inflammatory M2 phenotype on day 7. HA significantly ameliorated heat stress-induced proximal tubular damage and kidney fibrosis. HA substantially increased heat shock protein 70 (Hsp70) expression in the tubules before heat stress and reduced an elevation of cleaved caspase-3 expression after heat stress. HA also induced the Hsp70 expression of resident macrophages and prevented heat stress-induced changes in both subsets of kidney macrophages. These results provide pathophysiological data supporting the renoprotective effect of HA. Further studies are needed to confirm that HA can prevent kidney damage due to heat stress in humans.
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Affiliation(s)
- Hiroyasu Goto
- Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Masahiro Nakashima
- Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Hiroyuki Nakashima
- Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Midori Noguchi
- Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Toshihiko Imakiire
- Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Naoki Oshima
- Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Manabu Kinoshita
- Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Hiroo Kumagai
- Department of Nephrology and Endocrinology, National Defense Medical College, Tokorozawa, Saitama, Japan
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Fenemor S, Driller MW, Gill N, Mills B, Casadio J, Beaven CM. Practical application of a mixed active and passive heat acclimation protocol in elite male Olympic team sport athletes. Appl Physiol Nutr Metab 2022; 47:981-991. [PMID: 35793560 DOI: 10.1139/apnm-2022-0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate effectiveness and retention of heat acclimation (HA) integrated within an elite rugby sevens team training program, 12 elite male rugby sevens athletes undertook 10-days of mixed active/passive HA across two-weeks of normal training. Physiological and performance variables were assessed using a sport specific, repeated high-intensity heat-response test Pre-HA; after five days (Mid-HA); after 10 days (Post-HA); and 16-days post-HA (Decay). Resting, submaximal, and end-exercise core temperature were lower at Mid-HA (≤ -0.26 °C; d ≥-0.47), Post-HA (≤ -0.30 °C; d ≥-0.72), and Decay (≤ -0.29 °C; d ≥-0.56), compared to Pre-HA. Sweat rate was greater Post-HA compared to Pre-HA (0.3 ± 0.3 L·hr-1; d =0.63). Submaximal HR was lower at Mid (-9 ±4 bpm; d =-0.68) and Post-HA (-11 ± 4 bpm; d =-0.90) compared to Pre-HA. Mean and peak 6-s power output improved Mid-HA (83 ± 52 W; 112 ± 67 W; d ≥0.47) and Post-HA (125 ± 62 W; 172 ± 85 W; d ≥0.72) compared to Pre-HA. Improvements in HR and performance persisted at Decay (d ≥0.66). The initial five days of mixed-methods HA elicited many typical HA adaptations, with an additional five days eliciting further thermoregulatory, sudomotor, and performance improvements. Adaptations were well-retained after 16-days of normal training, without any further heat stimulus. The trial was retrospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622000732785).
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Affiliation(s)
- Stephen Fenemor
- University of Waikato, 3717, Te Huataki Waiora School of Health, Adams Centre for High Performance, Tauranga, Waikato, New Zealand.,High Performance Sport New Zealand, 540744, Auckland, New Zealand;
| | - Matthew W Driller
- La Trobe University School of Allied Health Human Services and Sport, 110570, Sport and Exercise Science, Bundoora, Victoria, Australia;
| | - Nicholas Gill
- University of Waikato, 3717, Te Huataki Waiora School of Health, Adams Centre for High Performance, Tauranga, Waikato, New Zealand.,New Zealand Rugby Union, Wellington, New Zealand;
| | - Blair Mills
- New Zealand Rugby Union, Wellington, New Zealand;
| | - Julia Casadio
- High Performance Sport New Zealand, 540744, Auckland, New Zealand;
| | - Christopher Martyn Beaven
- University of Waikato, 3717, Te Huataki Waiora School of Health, Adams Centre for High Performance, Tauranga, Waikato, New Zealand;
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89
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Romaszko J, Dragańska E, Jalali R, Cymes I, Glińska-Lewczuk K. Universal Climate Thermal Index as a prognostic tool in medical science in the context of climate change: A systematic review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154492. [PMID: 35278561 DOI: 10.1016/j.scitotenv.2022.154492] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 01/17/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
The assessment of the impact of meteorological factors on the epidemiology of various diseases and on human pathophysiology and physiology requires a comprehensive approach and new tools independent of currently occurring climate change. The thermal comfort index, i.e., Universal Climate Thermal Index (UTCI), is gaining more and more recognition from researchers interested in such assessments. This index facilitates the evaluation of the impact of cold stress and heat stress on the human organism and the assessment of the incidence of weather-related diseases. This work aims at identifying those areas of medical science for which the UTCI was applied for scientific research as well as its popularization among clinicians, epidemiologists, and specialists in public health management. This is a systematic review of literature found in Pubmed, Sciencedirect and Web of Science databases from which, consistent with PRISMA guidelines, original papers employing the UTCI in studies related to health, physiological parameters, and epidemiologic applications were extracted. Out of the total number of 367 papers identified in the databases, 33 original works were included in the analysis. The selected publications were analyzed in terms of determining the areas of medical science in which the UTCI was applied. The majority of studies were devoted to the broadly understood mortality, cardiac events, and emergency medicine. A significant disproportion between publications discussing heat stress and those utilizing the UTCI for its assessment was revealed.
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Affiliation(s)
- Jerzy Romaszko
- Department of Family Medicine and Infectious Diseases, School of Medicine, University of Warmia and Mazury in Olsztyn, Poland.
| | - Ewa Dragańska
- Department of Water Management and Climatology, University of Warmia and Mazury in Olsztyn, Poland
| | - Rakesh Jalali
- School of Medicine, Department of Emergency Medicine, University of Warmia and Mazury in Olsztyn, Poland
| | - Iwona Cymes
- Department of Water Management and Climatology, University of Warmia and Mazury in Olsztyn, Poland
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90
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Coudevylle GR, Collado A, Sinnapah S, Hue O, Robin N. Cold Suggestion to Cope with the Negative Impact of Tropical Climate. AMERICAN JOURNAL OF PSYCHOLOGY 2022. [DOI: 10.5406/19398298.135.2.04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
The thermal discomfort experienced in a tropical environment has negative effects on human performance. Cooling techniques before, during, or immediately after exercise have been extensively reported on in the physiological literature, but psychological techniques for subjective cooling have rarely been explored. The purpose of this experiment was to evaluate whether a cold suggestion would have an effect on environmental perceptions and affect in a tropical climate. Fifty participants were assigned in random order to two experimental sessions in similar hot and humid conditions at a 1-week interval (30°C ± 1.2; 87% rH ± 2): one with a suggestion focused on cold and the other a control session. The main results indicated that the suggestion focused on cold significantly decreased thermal discomfort and perceived heat and reduced the degradation on the Feeling Scale. The cold suggestion used as a per-cooling technique to cope with the negative impact of a tropical climate is discussed.
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91
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de Korte JQ, Veenstra BJ, van Rijswick M, Derksen EJK, Hopman MTE, Bongers CCWG, Eijsvogels TMH. A Heart Rate Based Algorithm to Estimate Core Temperature Responses in Elite Athletes Exercising in the Heat. Front Sports Act Living 2022; 4:882254. [PMID: 35813051 PMCID: PMC9256956 DOI: 10.3389/fspor.2022.882254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/20/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Non-invasive non-obtrusive continuous and real-time monitoring of core temperature (Tc) may enhance pacing strategies, the efficacy of heat mitigation measures, and early identification of athletes at risk for heat-related disorders. The Estimated Core Temperature (ECTemp™) algorithm uses sequential heart rate (HR) values to predict Tc. We examined the validity of ECTemp™ among elite athletes exercising in the heat. Methods 101 elite athletes performed an exercise test in simulated hot and humid environmental conditions (ambient temperature: 31.6 ± 1.0°C, relative humidity: 74 ± 5%). Tc was continuously measured using a validated ingestible telemetric temperature capsule system. In addition, HR was continuously measured and used to compute the estimated core temperature (Tc-est) using the ECTemp™ algorithm. Results Athletes exercised for 44 ± 10 min and n = 5,025 readouts of Tc (range: 35.8-40.4°C), HR (range: 45-207 bpm), and Tc-est (range: 36.7-39.9°C) were collected. Tc-est demonstrated a small yet significant bias of 0.15 ± 0.29°C (p < 0.001) compared to Tc, with a limit of agreement of ±0.45°C and a root mean square error of 0.35 ± 0.18°C. Utilizing the ECTemp™ algorithm as a diagnostic test resulted in a fair to excellent sensitivity (73-96%) and specificity (72-93%) for Tc-est thresholds between 37.75 and 38.75°C, but a low to very-low sensitivity (50-0%) for Tc-est thresholds >39.0°C, due to a high prevalence of false-negative observations. Conclusion ECTemp™ provides a valuable and representative indication of thermal strain in the low- to mid-range of Tc values observed during exercise in the heat. It may, therefore, be a useful non-invasive and non-obtrusive tool to inform athletes and coaches about the estimated core temperature during controlled hyperthermia heat acclimation protocols. However, the ECTemp™ algorithm, in its current form, should not solely be used to identify athletes at risk for heat-related disorders due to low sensitivity and high false-negative rate in the upper end of the Tc spectrum.
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Affiliation(s)
- Johannus Q. de Korte
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
| | - Bertil J. Veenstra
- Institute of Training Medicine & Training Physiology, TGTF, Royal Netherlands Army, Utrecht, Netherlands
| | - Mark van Rijswick
- Institute of Training Medicine & Training Physiology, TGTF, Royal Netherlands Army, Utrecht, Netherlands
| | - Eline J. K. Derksen
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
| | - Maria T. E. Hopman
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
| | - Coen C. W. G. Bongers
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
| | - Thijs M. H. Eijsvogels
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, Netherlands
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92
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Temporal Skin Temperature as an Indicator of Cardiorespiratory Fitness Assessed with Selected Methods. BIOLOGY 2022; 11:biology11070948. [PMID: 36101329 PMCID: PMC9311827 DOI: 10.3390/biology11070948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 11/16/2022]
Abstract
The aim of this study was to determine whether there are associations between cardiovascular fitness (and aerobic capacity) and changes in temporal skin temperature during and after a single bout of high-intensity exercise. Twenty-three men with varying levels of physical activity (VO2max: 59.03 ± 11.19 (mL/kg/min), body mass 71.5 ± 10.4 (kg), body height 179 ± 8 (cm)) participated in the study. Each subject performed an incremental test and, after a 48-h interval, a 110%Pmax power test combined with an analysis of the thermal parameters, heart rate recovery and heart rate variability. Thermal radiation density from the body surface (temple) was measured using a Sonel KT384 thermal imaging camera immediately after warm-up (Tb), immediately after exercise (Te) and 120 sec after the end of exercise (Tr). The differences between measurements were then calculated. The correlation analysis between the thermal and cardiovascular function parameters during the recovery period showed strong positive associations between the Tr-Te difference and measures of cardiovascular fitness (50 < r < 69, p < 0.05). For example, the correlation coefficient between Tr-Te and VO2max reached 0.55 and between Tr-Te and Pmax reached 0.68. The results obtained indicate that the measurement of temporal temperature during and after an intense 3-min bout of exercise can be used to assess aerobic physical capacity and cardiovascular fitness.
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93
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Sumi D, Nagatsuka H, Matsuo K, Okazaki K, Goto K. Heat acclimation does not attenuate hepcidin elevation after a single session of endurance exercise under hot condition. Eur J Appl Physiol 2022; 122:1965-1974. [PMID: 35674827 PMCID: PMC9174628 DOI: 10.1007/s00421-022-04974-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/17/2022] [Indexed: 12/05/2022]
Abstract
Purpose We sought to determine the effects of heat acclimation on endurance exercise-induced hepcidin elevation under hot conditions. Methods Fifteen healthy men were divided into two groups: endurance training under hot conditions (HOT, 35 °C, n = 8) and endurance training under cool conditions (CON, 18 °C, n = 7). All subjects completed 10 days of endurance training (8 sessions in total), consisting of 60 min of continuous exercise at 50% of maximal oxygen uptake (\documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2\max }$$\end{document}V˙O2max) under their assigned environment condition. Subjects completed a heat stress exercise test (HST, 60 min exercise at 60% \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2\max }$$\end{document}V˙O2max) to evaluate the exercise-induced thermoregulatory and hepcidin responses under hot conditions (35 °C) before (pre-HST) and after (post-HST) the training period. Results Core temperature during exercise in the post-HST decreased significantly in the HOT group compared to pre-HST (P = 0.004), but not in the CON group. The HOT and CON groups showed augmented exercise-induced plasma interleukin-6 (IL-6) elevation in the pre-HST (P = 0.002). Both groups had significantly attenuated increases in exercise-induced IL-6 in the post-HST; however, the reduction of exercise-induced IL-6 elevation was not different significantly between both groups. Serum hepcidin concentrations increased significantly in the pre-HST and post-HST in both groups (P = 0.001), no significant difference was observed between both groups during each test or over the study period. Conclusion 10 days of endurance training period under hot conditions improved thermoregulation, whereas exercise-induced hepcidin elevation under hot conditions was not attenuated following the training.
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Affiliation(s)
- Daichi Sumi
- Research Center for Urban Health and Sports, Osaka City University, Osaka, Osaka, Japan
- Research Fellow of Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
| | - Haruna Nagatsuka
- Graduate School of Sports and Health Science, Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kaori Matsuo
- Department of Rehabilitation, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Kurashiki, Okayama, Japan
| | - Kazunobu Okazaki
- Research Center for Urban Health and Sports, Osaka City University, Osaka, Osaka, Japan
| | - Kazushige Goto
- Graduate School of Sports and Health Science, Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
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Effects of Heat Acclimation Following Heat Acclimatization on Whole Body Heat Exchange in Trained Endurance Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19116412. [PMID: 35681997 PMCID: PMC9180767 DOI: 10.3390/ijerph19116412] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to examine the changes in metabolic heat production (Hprod), evaporative heat loss (Hevap), and dry heat loss (Hdry), following heat acclimatization (HAz) and heat acclimation (HA). Twenty-two male endurance athletes (mean ± standard deviation; age, 37 ± 12 y; body mass, 73.4 ± 8.7 kg; height, 178.7 ± 6.8 cm; and VO2max, 57.1 ± 7.2 mL·kg−1·min−1) completed three trials (baseline; post-HAz; and post-HA), which consisted of 60 min steady state exercise at 59 ± 2% velocityVO2max in the heat (ambient temperature [Tamb], 35.2 ± 0.6 °C; relative humidity [%rh] 47.5 ± 0.4%). During the trial, VO2 and RER were collected to calculate Hprod, Hevap, and Hdry. Following the baseline trial, participants completed self-directed outdoor summer training followed by a post-HAz trial. Then, five days of HA were completed over eight days in the heat (Tamb, 38.7 ± 1.1 °C; %rh, 51.2 ± 2.3%). During the HA sessions, participants exercised to maintain hyperthermia (38.50 °C and 39.75 °C) for 60 min. Then, a post-HA trial was performed. There were no differences in Hprod between the baseline (459 ± 59 W·m−2), post-HAz (460 ± 61 W·m−2), and post-HA (464 ± 55 W·m−2, p = 0.866). However, Hevap was significantly increased post-HA (385 ± 84 W·m−2) compared to post-HAz (342 ± 86 W·m−2, p = 0.043) and the baseline (332 ± 77 W·m−2, p = 0.037). Additionally, Hdry was significantly lower at post-HAz (125 ± 8 W·m−2, p = 0.013) and post-HA (121 ± 10 W·m−2, p < 0.001) compared to the baseline (128 ± 7 W·m−2). Hdry at post-HA was also lower than post-HAz (p = 0.049). Hprod did not change following HAz and HA. While Hdry was decreased following HA, the decrease in Hdry was smaller than the increases in Hevap. Adaptations in body heat exchange can occur by HA following HAz.
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Marathon Performance and Pacing in the Doha 2019 Women's IAAF World Championships: Extreme Heat, Suboptimal Pacing, and High Failure Rates. Int J Sports Physiol Perform 2022; 17:1119-1125. [PMID: 35580843 DOI: 10.1123/ijspp.2022-0020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE The Doha 2019 women's World Championship marathon took place in extreme hot (32 °C), humid conditions (74% relative humidity) culminating in unprecedented (41%) failure rates. We explored whether extreme heat or suboptimal pacing was responsible for diminished performance against a temperate "control" (London 2017: 19 °C, 59% relative humidity) and whether physical characteristics (eg, body surface area, estimated maximal oxygen uptake, habitual heat exposure) explained performance. METHOD Five-kilometer-pace (km·h-1) data underwent repeated-measures analyses of hot (Doha, n = 40) versus temperate pacing and performance (London, n = 78) within and between marathon pacing (finisher quartiles normalized against personal best; n = 10 per group) and within hot marathon finishers versus nonfinishers (up to 10 km; normalized data). Possible predictors (multiple regression) of hot marathon pacing were explored. Tests to .05 alpha level, partial eta squared (ηp2) indicates effect size. RESULTS Mean (SD) of Doha (14.82 [0.96] km·h-1) pace was slower (London: 15.74 [0.96] km·h-1; P = .00; ηp2=.500). In hot conditions, athletes finishing in positions 1 to 10 (group 1) started more conservatively (93.7% [2.1%] of personal best) than slower runners (groups 3 and 4; 96.6% [2.8%] of personal best; P < .05, ηp2=.303). Groups were not different at 15 km and then slowed immediately (groups 3 and 4) or after 20 km (group 2). Finishers and nonfinishers adopted similar pace up to 10 km (P > .05, ηp2=.003). World ranking predicted (P = .00; r2 = .248) average pace in Doha. CONCLUSION Extreme hot conditions reduced performance. Top 10 athletes adopted a conservative initial pace, whereas lower-placing athletes adopted a faster, aggressive start. Pacing alone does not explain high failure rates in nonfinishers. Athletes competing in the heat should initially pace conservatively to optimize performance.
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96
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Stone BL, Ashley JD, Skinner RM, Polanco JP, Walters MT, Schilling BK, Kellawan JM. Effects of a Short-Term Heat Acclimation Protocol in Elite Amateur Boxers. J Strength Cond Res 2022; 36:1966-1971. [PMID: 35510889 DOI: 10.1519/jsc.0000000000004233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Stone, BL, Ashley, JD, Skinner, RM, Polanco, JP, Walters, MT, Schilling, BK, and Kellawan, JM. Effects of a short-term heat acclimation protocol in elite amateur boxers. J Strength Cond Res XX(X): 000-000, 2022-Boxing requires proficient technical and tactical skills coupled with high levels of physiological capacity. Although heat and humidity negatively affect acute exercise performance, short-term exercise training in hot and humid environments can lead to physiological adaptations that enhance exercise performance in both hot and thermoneutral conditions. In highly trained endurance athletes, exercise-induced acclimation can occur in as little as 5 days (known as short-term heat acclimation [STHA]). However, the impact of a 5-day heat acclimation (5-DayHA) in combat athletes, such as elite amateur boxers, is unknown. The aim of the present investigation was to determine whether a 5-DayHA improves aerobic performance in a thermoneutral environment and causes positive physiological adaptations in elite boxers. Seven elite amateur boxers underwent a 5-DayHA protocol, consisting of 60-minute exercise sessions in an environmental chamber at 32 °C and 70% relative humidity. Repeat sprint test (RST) evaluated aerobic performance in a thermoneutral environment 24 hours before and after the 5-DayHA. Presession and postsession hydration status (urine specific gravity) and body mass were assessed. After a 5-DayHA period, boxers significantly improved RST performance (13 ± 7 to 19 ± 7 sprints, d = 0.92, p = 0.03) but not pre-exercise hydration status (1.02 ± 0.01 to 1.01 ± 0.01, d = 0.82, p = 0.07). Therefore, these findings suggest 5-DayHA enhances aerobic performance in elite-level amateur boxers and may provide a viable training option for elite combat athletes.
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Affiliation(s)
- Brandon L Stone
- Human Circulation Research Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma.,Sport Sciences, U.S. Olympic Committee, Colorado Springs, Colorado.,Applied Research, Toronto Blue Jays Baseball Club, Dunedin, Florida
| | - John D Ashley
- Human Circulation Research Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma
| | - Robert M Skinner
- Sport Sciences, U.S. Olympic Committee, Colorado Springs, Colorado
| | - Jose P Polanco
- Sport Sciences, U.S. Olympic Committee, Colorado Springs, Colorado
| | - Mason T Walters
- Sport Sciences, U.S. Olympic Committee, Colorado Springs, Colorado.,Department of Health Sciences, University of Colorado at Colorado Springs, Colorado Springs, Colorado; and
| | - Brian K Schilling
- Kinesiology and Nutrition Sciences, University of Nevada-Las Vegas, Las Vegas, Nevada
| | - J M Kellawan
- Human Circulation Research Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma
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97
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Renberg J, Lignier MJ, Wiggen ØN, Færevik H, Helgerud J, Sandsund M. Heat tolerance during uncompensable heat stress in men and women wearing firefighter personal protective equipment. APPLIED ERGONOMICS 2022; 101:103702. [PMID: 35121406 DOI: 10.1016/j.apergo.2022.103702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/21/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Firefighters run a risk of heat strain during occupational tasks. The number of female firefighters has been increasing, but research relevant to this group is still scarce. We aimed to investigate whether there are any sex differences in heat tolerance or physiological responses during uncompensable heat stress while wearing firefighter personal protective equipment. Twelve female (28 ± 7 years, 66 ± 5 kg, 51.7 ± 4.7 mL kg-1 min-1) and 12 male (27 ± 7 years, 83 ± 8 kg, 58.8 ± 7.5 mL kg-1 min-1) participants performed walking (maximum of 60 min) at 6W·kg-1, 40 °C, and 14% relative humidity. No differences were observed between groups in heat tolerance, rectal temperature, heart rate, percent body mass loss, thermal sensation, and rate of perceived exertion. Thus, when personnel are selected using gender-neutral physical employment standards, sex is not an independent factor influencing heat tolerance when wearing firefighter personal protective equipment during uncompensable heat stress.
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Affiliation(s)
- Julie Renberg
- SINTEF Digital, Department of Health Research, Trondheim, Norway.
| | - Maxime Jeanovitch Lignier
- Norwegian University of Science and Technology (NTNU), Department of Neuromedicine and Movement Science, Trondheim, Norway
| | | | - Hilde Færevik
- SINTEF Digital, Department of Health Research, Trondheim, Norway
| | - Jan Helgerud
- Norwegian University of Science and Technology (NTNU), Department of Circulation and Medical Imaging, Trondheim, Norway; Myworkout, Medical Rehabilitation Centre, Trondheim, Norway
| | - Mariann Sandsund
- SINTEF Digital, Department of Health Research, Trondheim, Norway
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98
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Heat Acclimation with or without Normobaric Hypoxia Exposure Leads to Similar Improvements in Endurance Performance in the Heat. Sports (Basel) 2022; 10:sports10050069. [PMID: 35622478 PMCID: PMC9147627 DOI: 10.3390/sports10050069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/19/2022] [Accepted: 04/26/2022] [Indexed: 11/17/2022] Open
Abstract
Background: Combining the key adaptation of plasma volume (PV) expansion with synergistic physiological effects of other acclimation interventions to maximise endurance performance in the heat has potential. The current study investigated the effects of heat acclimation alone (H), combined with normobaric hypoxia exposure (H+NH), on endurance athletic performance. Methods: Well-trained participants completed a heat-stress trial (30 °C, 80% relative humidity (RH), 20.8% fraction of inspired oxygen (FiO2)) of a 75 min steady-state cycling (fixed workload) and a subsequent 15 min cycling time trial for distance before and after intervention. Participants completed 12 consecutive indoor training days with either heat acclimation (H; 60 min·day−1, 30 °C, 80% RH; 20.8% FiO2) or heat acclimation and overnight hypoxic environment (H+NH; ~12 h, 60% RH; 16% FiO2 simulating altitude of ~2500 m). Control (CON) group trained outdoors with average maximum daily temperature of 16.5 °C and 60% RH. Results: Both H and H+NH significantly improved time trial cycling distance by ~5.5% compared to CON, with no difference between environmental exposures. PV increased (+3.8%) and decreased (−4.1%) following H and H+NH, respectively, whereas haemoglobin concentration decreased (−2%) and increased (+3%) in H and H+NH, respectively. Conclusion: Our results show that despite contrasting physiological adaptations to different environmental acclimation protocols, heat acclimation with or without hypoxic exposure demonstrated similar improvements in short-duration exercise performance in a hot environment.
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99
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Ioannou LG, Foster J, Morris NB, Piil JF, Havenith G, Mekjavic IB, Kenny GP, Nybo L, Flouris AD. Occupational heat strain in outdoor workers: A comprehensive review and meta-analysis. Temperature (Austin) 2022; 9:67-102. [PMID: 35655665 PMCID: PMC9154804 DOI: 10.1080/23328940.2022.2030634] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 12/29/2022] Open
Abstract
The present comprehensive review (i) summarizes the current knowledge on the impacts of occupational heat stress on outdoor workers, (ii) provides a historical background on this issue, (iii) presents a meta-analysis of published data, (iv) explores inter-individual and intra-individual factors, (v) discusses the available heat mitigation strategies, (vi) estimates physical work capacity, labour productivity, and metabolic rate for the year 2030, and (vii) provides an overview of existing policy and legal frameworks on occupational heat exposure. Meta-analytic findings from 38 field studies that involved monitoring 2,409 outdoor workers across 41 jobs in 21 countries suggest that occupational heat stress increases the core (r = 0.44) and skin (r = 0.44) temperatures, as well as the heart rate (r = 0.38) and urine specific gravity (r = 0.13) of outdoor workers (all p < 0.05). Moreover, it diminishes the capacity of outdoor workers for manual labour (r = -0.82; p < 0.001) and is responsible for more than two thirds of the reduction in their metabolic rate. Importantly, our analysis shows that physical work capacity is projected to be highly affected by the ongoing anthropogenic global warming. Nevertheless, the metabolic rate and, therefore, labour productivity are projected to remain at levels higher than the workers' physical work capacity, indicating that people will continue to work more intensely than they should to meet their financial obligations for food and shelter. In this respect, complementary measures targeting self-pacing, hydration, work-rest regimes, ventilated garments, and mechanization can be adopted to protect outdoor workers.
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Affiliation(s)
- Leonidas G. Ioannou
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - Josh Foster
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nathan B. Morris
- Department of Human Physiology & Nutrition, University of Colorado, Springs, Colorado, USA
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, August Krogh Building, University of Copenhagen, Copenhagen, Denmark
| | - Andreas D. Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
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100
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Abstract
Background Physiological heat adaptations can be induced following various protocols that use either artificially controlled (i.e. acclimation) or naturally occurring (i.e. acclimatisation) environments. During the summer months in seasonal climates, adequate exposure to outdoor environmental heat stress should lead to transient seasonal heat acclimatisation. Objectives The aim of the systematic review was to assess the available literature and characterise seasonal heat acclimatisation during the summer months and identify key factors that influence the magnitude of adaptation. Eligibility Criteria English language, full-text articles that assessed seasonal heat acclimatisation on the same sample of healthy adults a minimum of 3 months apart were included. Data Sources Studies were identified using first- and second-order search terms in the databases MEDLINE, SPORTDiscus, CINAHL Plus with Full Text, Scopus and Cochrane, with the last search taking place on 15 July 2021. Risk of Bias Studies were independently assessed by two authors for the risk of bias using a modified version of the McMaster critical review form. Data Extraction Data for the following outcome variables were extracted: participant age, sex, body mass, height, body fat percentage, maximal oxygen uptake, time spent exercising outdoors (i.e. intensity, duration, environmental conditions), heat response test (i.e. protocol, time between tests), core temperature, skin temperature, heart rate, whole-body sweat loss, whole-body and local sweat rate, sweat sodium concentration, skin blood flow and plasma volume changes. Results Twenty-nine studies were included in this systematic review, including 561 participants across eight countries with a mean summer daytime wet-bulb globe temperature (WBGT) of 24.9 °C (range: 19.5–29.8 °C). Two studies reported a reduction in resting core temperature (0.16 °C; p < 0.05), 11 reported an increased sweat rate (range: 0.03–0.53 L·h−1; p < 0.05), two observed a reduced heart rate during a heat response test (range: 3–8 beats·min−1; p < 0.05), and six noted a reduced sweat sodium concentration (range: − 22 to − 59%; p < 0.05) following summer. The adaptations were associated with a mean summer WBGT of 25.2 °C (range: 19.6–28.7 °C). Limitations The available studies primarily focussed on healthy male adults and demonstrated large differences in the reporting of factors that influence the development of seasonal heat acclimatisation, namely, exposure time and duration, exercise task and environmental conditions. Conclusions Seasonal heat acclimatisation is induced across various climates in healthy adults. The magnitude of adaptation is dependent on a combination of environmental and physical activity characteristics. Providing environmental conditions are conducive to adaptation, the duration and intensity of outdoor physical activity, along with the timing of exposures, can influence seasonal heat acclimatisation. Future research should ensure the documentation of these factors to allow for a better characterisation of seasonal heat acclimatisation. PROSPERO Registration CRD42020201883. Supplementary Information The online version contains supplementary material available at 10.1007/s40279-022-01677-0.
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